Gigabyte (GB) - Unit Information & Conversion

Quick Answer: What is a Gigabyte?

A gigabyte (GB) is a unit of digital storage equal to 1,000,000,000 bytes (one billion bytes). It's the standard unit for measuring storage capacity of hard drives, SSDs, USB flash drives, and file sizes for movies, software, and games. 1 GB = 1,000 megabytes (MB) or 0.001 terabytes (TB). For reference: a typical 1080p movie is 3-5 GB, a modern smartphone photo is 3-5 MB (about 200-300 photos per GB), and a PC game installation ranges from 20-150 GB. Important distinction: 1 GB (gigabyte) ≠ 1 GiB (gibibyte)—the gibibyte is 7.37% larger (1,073,741,824 bytes), which explains why a "500 GB" drive shows as 465 GiB in Windows.

Comparison Table

Storage Amount	Gigabytes (GB)	Megabytes (MB)	Terabytes (TB)	Gibibytes (GiB)
Smartphone photo	0.003-0.005 GB	3-5 MB	0.000003-0.000005 TB	0.0028-0.0047 GiB
MP3 song (4 min)	0.004 GB	4 MB	0.000004 TB	0.0037 GiB
High-res photo	0.008-0.015 GB	8-15 MB	0.000008-0.000015 TB	0.0075-0.014 GiB
Standard album	0.05 GB	50 MB	0.00005 TB	0.047 GiB
One gigabyte	1 GB	1,000 MB	0.001 TB	0.9313 GiB
1080p movie	4-5 GB	4,000-5,000 MB	0.004-0.005 TB	3.73-4.66 GiB
Dual-layer DVD	8.5 GB	8,500 MB	0.0085 TB	7.92 GiB
Modern PC game	50-150 GB	50,000-150,000 MB	0.05-0.15 TB	46.6-139.7 GiB
4K UHD movie	25-50 GB	25,000-50,000 MB	0.025-0.05 TB	23.3-46.6 GiB
One terabyte	1,000 GB	1,000,000 MB	1 TB	931.3 GiB

Explore related data storage units: megabyte • terabyte • gibibyte • byte • kilobyte

Definition

A gigabyte (GB) is a unit of digital information storage equal to 10⁹ bytes (one billion bytes). It uses the standard SI decimal prefix 'giga-'. One gigabyte is equivalent to 1,000 megabytes (MB).

Precise definitions:

• 1 gigabyte (GB) = 1,000,000,000 bytes (exactly 10⁹)
• 1 GB = 1,000 megabytes (MB)
• 1 GB = 1,000,000 kilobytes (KB)
• 1 GB = 8,000,000,000 bits (8 billion bits)
• 1 GB = 0.001 terabytes (TB)

Relationship to binary units:

• 1 gigabyte (GB) ≈ 0.9313 gibibytes (GiB)
• 1 gibibyte (GiB) = 1,073,741,824 bytes = 2³⁰ bytes
• 1 GiB ≈ 1.074 GB (7.37% larger)

Gigabyte (GB) vs. Gibibyte (GiB): Critical Distinction

This is the source of the infamous "missing storage" confusion:

Gigabyte (GB) — Decimal prefix:

• Exactly 1,000,000,000 bytes (10⁹)
• Based on SI standard (powers of 10)
• Used by storage manufacturers (hard drives, SSDs, USB drives)
• Used for data transfer rates, internet speeds, data plans
• Marketing and advertising standard

Gibibyte (GiB) — Binary prefix:

• Exactly 1,073,741,824 bytes (2³⁰)
• Based on binary powers (powers of 2)
• Used by Windows, Linux, macOS for storage reporting
• Used in RAM specifications (though often mislabeled as "GB")
• Technical documentation standard

Why your "500 GB" drive shows as "465 GB" in Windows:

• Manufacturer's claim: 500 GB = 500,000,000,000 bytes
• Windows calculation: 500,000,000,000 ÷ 1,073,741,824 = 465.66 GiB
• Windows displays this as: "465 GB" (but actually means 465 GiB)
• Result: Appears to have "lost" 35 GB, but it's just a unit conversion

Percentage difference: GiB is 7.37% larger than GB, so the gap widens with larger capacities:

• 100 GB = 93.13 GiB (6.87 GB "missing")
• 500 GB = 465.66 GiB (34.34 GB "missing")
• 1 TB = 931.32 GiB (68.68 GB "missing")
• 2 TB = 1,862.65 GiB (137.35 GB "missing")

Gigabyte (GB) vs. Gigabit (Gb): Don't Confuse Them!

Another critical distinction:

Gigabyte (GB):

• Measures storage capacity (data at rest)
• 1 GB = 1,000,000,000 bytes
• Used for: file sizes, storage devices, data plans
• Symbol: GB (capital B for Byte)

Gigabit (Gb or Gbit):

• Measures data transfer speed (data in motion)
• 1 Gb = 1,000,000,000 bits
• Used for: network speeds, internet connections
• Symbol: Gb or Gbit (lowercase b for bit)
• 1 gigabyte = 8 gigabits (since 1 byte = 8 bits)

Real-world example:

• 1 Gbps (gigabit per second) internet connection can theoretically download at 125 MB/s (megabytes per second) or 0.125 GB/s
• Calculation: 1 Gbps ÷ 8 = 0.125 GB/s
• In practice: Overhead reduces this to ~100-115 MB/s actual download speed

History

The prefix 'giga-' (meaning billion) was adopted as an SI prefix in 1960. Its application to the byte (gigabyte) became widespread with the increasing capacity of computer storage media like hard drives in the 1980s and 1990s.

The "Giga-" Prefix Origins (1960)

International standardization:

1960: 11th General Conference on Weights and Measures (CGPM):

• Officially adopted "giga-" as the SI prefix for one billion (10⁹)
• Derived from Greek "γίγας" (gigas) meaning "giant"
• Part of the expanded SI prefix system: kilo (10³), mega (10⁶), giga (10⁹), tera (10¹²)

Scientific context before computing:

• Originally used in physics and engineering (gigahertz, gigawatt, gigajoule)
• Computing adopted SI prefixes as storage capacity grew

Early Gigabyte Storage (1980s-1990s)

When gigabytes became practical:

1985: IBM 3380 Direct Access Storage Device:

• First mainstream storage system with multi-gigabyte capacity (up to 2.52 GB per unit)
• Used by mainframe computers
• Cost: Approximately $100,000+ per unit
• $40,000-$50,000 per gigabyte

1991: IBM 0663 Corsair:

• First consumer hard drive exceeding 1 GB (1.05 GB capacity)
• 3.5-inch form factor
• Price: $2,799 (approximately $2,665 per GB)
• Revolutionary for personal computing—suddenly PCs could store hundreds of applications

1997: Hard drive prices drop below $1,000/GB:

• Typical 4 GB drive: $300-$400 ($75-$100 per GB)
• Enabled multimedia computing (video editing, game installations)

Late 1990s: CD-ROMs reach 650-700 MB:

• A single CD held 0.65-0.7 GB
• Software distribution moved from floppy disks (1.44 MB) to CDs
• Games and applications could be hundreds of megabytes

The GB vs. GiB Ambiguity Crisis (1960s-1998)

Decades of confusion:

The root problem: Computer memory uses binary addressing (powers of 2), but SI prefixes are decimal (powers of 10).

1960s-1990s: Binary interpretation becomes common:

• Computer scientists used "kilobyte" = 1,024 bytes (2¹⁰), not 1,000
• "Megabyte" = 1,048,576 bytes (2²⁰), not 1,000,000
• "Gigabyte" = 1,073,741,824 bytes (2³⁰), not 1,000,000,000
• Rationale: Memory addresses are binary, so powers of 2 made sense

1980s-1990s: Storage manufacturers use decimal:

• Hard drive makers used 1 GB = 1,000,000,000 bytes (exact SI definition)
• Marketing advantage: Decimal prefixes made drives appear larger
• Example: 100 billion bytes marketed as "100 GB" (decimal) showed as "93.13 GB" in Windows (binary)

Consumer confusion and lawsuits:

• "Missing storage" complaints: Consumers felt deceived when drives appeared smaller than advertised
• 2006: Western Digital lawsuit: Settled for marketing "400 GB" drives that showed as 372 GB in Windows
• Apple, Seagate, others: Similar lawsuits alleging deceptive marketing

IEC Binary Prefix Solution (1998-Present)

Official standardization to end confusion:

1998: IEC introduces binary prefixes (IEC 60027-2 standard):

• Kibibyte (KiB) = 1,024 bytes (2¹⁰)
• Mebibyte (MiB) = 1,048,576 bytes (2²⁰)
• Gibibyte (GiB) = 1,073,741,824 bytes (2³⁰)
• Tebibyte (TiB) = 1,099,511,627,776 bytes (2⁴⁰)

Result: "Gigabyte" (GB) officially reserved for exactly 1 billion bytes (10⁹)

2008: ISO/IEC 80000 standard reinforces binary prefixes:

• International standard formally distinguishes GB (decimal) from GiB (binary)

Current adoption status:

• Storage manufacturers: Universally use GB (decimal)
• Operating systems: Mixed—Linux increasingly uses GiB, Windows still shows "GB" but calculates in GiB, macOS uses GB (decimal) since 10.6
• RAM specifications: Technically should use GiB, but often marketed as "GB" (e.g., "16 GB RAM" actually means 16 GiB)

Modern Era (2000s-Present)

Gigabytes become consumer standard:

2000s: Hard drives reach 100-500 GB:

• 2000: Typical drive 20-40 GB ($5-$10 per GB)
• 2005: Typical drive 160-250 GB ($0.50-$1 per GB)
• 2008: First consumer 1 TB drive (1,000 GB) from Hitachi
• Prices consistently drop following Moore's Law-like trends

2007: iPhone launched with 4-8 GB storage:

• Made gigabytes the standard for mobile devices
• Rapidly increased to 16-32-64 GB models

2010s: SSDs mainstream (128-512 GB typical):

• Solid-state drives offer speed advantages
• Initially expensive ($1-$2 per GB in 2010)
• By 2020: $0.10-$0.15 per GB for consumer SSDs

2020s: Terabytes become consumer standard, gigabytes for mobile:

• Typical laptop SSD: 256-512 GB (budget) to 1-2 TB (high-end)
• Typical desktop HDD: 1-4 TB
• Smartphones: 64-256 GB standard, flagships 512 GB-1 TB
• Cloud storage: 15 GB free (Google), 2 GB free (Dropbox), 5 GB free (iCloud)

Real-World Examples

Storage Device Capacities

Modern storage devices measured in gigabytes:

USB Flash Drives:

• 16 GB: Entry-level, budget option (~$3-$5)—stores 4,000 photos, 4,000 MP3 songs, or 3-4 movies
• 32 GB: Popular mid-range size (~$6-$8)—sufficient for document backup, photo transfer
• 64 GB: Common high-capacity option (~$10-$12)—bootable OS installers, large file transfers
• 128 GB: Professional/enthusiast choice (~$15-$20)—video projects, extensive file collections
• 256-512 GB: Available but uncommon (external SSDs more cost-effective at this size)

SD Cards (for cameras, drones, phones):

• 32 GB: Entry SDHC card—stores ~5,000 smartphone photos or 50 minutes 4K video
• 64 GB: Popular for consumer cameras—100 minutes 4K video or 10,000 high-res photos
• 128 GB: Enthusiast photographer/videographer standard—200 minutes 4K, 20,000+ photos
• 256 GB: Professional use—400+ minutes 4K, 40,000+ photos, 4K60fps video
• 512 GB-1 TB: High-end professional (technically half-terabyte to full terabyte)

Solid-State Drives (SSDs):

• 128 GB: Minimum usable PC storage—OS + basic programs (cramped for modern use)
• 256 GB: Budget laptop standard—OS, programs, moderate file storage
• 512 GB: Mid-range sweet spot—comfortable for most users, balanced price/capacity
• 1 TB (1,000 GB): High-end consumer standard—ample space for games, media, projects
• 2 TB: Enthusiast/professional—extensive game libraries, video editing, large datasets

Hard Disk Drives (HDDs) — budget bulk storage:

• 1 TB: Budget desktop/laptop HDD—legacy minimum capacity
• 2 TB: Common consumer desktop drive—bulk media storage
• 4 TB: Standard desktop storage drive—media servers, backup drives
• 8-12 TB: Prosumer/NAS (Network Attached Storage) drives
• 18-20 TB: Enterprise/datacenter drives (though measured in TB, worth noting GB relationship)

File Sizes by Type

How much can you fit in a gigabyte?

Photos:

• Smartphone photo (JPEG, 12 MP): 3-5 MB → 200-300 photos per GB
• DSLR photo (JPEG, 24 MP): 8-12 MB → 80-125 photos per GB
• RAW camera file (uncompressed): 25-50 MB → 20-40 photos per GB
• Professional RAW (50+ MP): 50-100 MB → 10-20 photos per GB

Music:

• MP3 (128 kbps, 4-minute song): ~4 MB → 250 songs per GB
• MP3 (320 kbps, high quality): ~10 MB → 100 songs per GB
• FLAC (lossless audio): ~30 MB → 33 songs per GB
• Typical album (12 songs, 320 kbps): ~120 MB → 8-9 albums per GB

Video:

• 1080p video (H.264, 30fps): ~1-1.5 GB per hour → 40-60 minutes per GB
• 1080p movie (2 hours, compressed): 3-5 GB total
• 4K video (H.264, 30fps): ~4-5 GB per hour → 12-15 minutes per GB
• 4K movie (2 hours, compressed): 25-50 GB total
• YouTube video (1080p, 10 minutes): ~150-300 MB → 3-7 videos per GB

Documents:

• Plain text file: ~2 KB → 500,000 text files per GB
• Word document (with images): ~500 KB → 2,000 documents per GB
• PDF (50-page report): ~5 MB → 200 PDFs per GB
• PowerPoint presentation: ~10-30 MB → 33-100 presentations per GB
• Excel spreadsheet (large dataset): ~10-50 MB → 20-100 spreadsheets per GB

Software and Games:

• Mobile app (typical): 50-200 MB → 5-20 apps per GB
• Desktop application (lightweight): 100-500 MB → 2-10 apps per GB
• Adobe Creative Suite app: 1-3 GB each
• PC game (indie/older): 2-10 GB
• PC game (modern AAA title): 50-150 GB (Call of Duty: ~100-150 GB, GTA V: ~94 GB, Red Dead Redemption 2: ~150 GB)
• Operating system: Windows 11 ~20-25 GB install, macOS ~15-20 GB, Linux 5-10 GB

Internet Data Plans and Usage

Mobile data plans (gigabytes per month):

Light user (1-3 GB/month):

• Web browsing: 100-300 hours
• Email: Thousands of text emails
• Social media: 10-30 hours (varies by video autoplay)
• Music streaming: 20-60 hours (varies by quality)

Moderate user (5-10 GB/month):

• Everything above, plus:
• Video streaming (SD 480p): 10-20 hours
• Video calls: 15-30 hours
• App downloads and updates

Heavy user (15-30 GB/month):

• Video streaming (HD 720p-1080p): 15-30 hours
• Social media with extensive video: 30-60 hours
• Frequent app downloads/updates
• Cloud photo backup (via cellular)

Unlimited plans (50+ GB/month before throttling):

• Many carriers throttle after 50-75 GB monthly usage
• Heavy 4K streaming: 10-20 GB per hour
• Hotspot tethering for laptop use

Data consumption rates:

• Web browsing: ~2-3 MB per page → 300-500 pages per GB
• Email (text only): ~10-50 KB → 20,000-100,000 emails per GB
• Spotify streaming (normal quality): ~70 MB/hour → 14 hours per GB
• Spotify streaming (high quality): ~150 MB/hour → 6-7 hours per GB
• Netflix SD (480p): ~0.7 GB/hour → 1.4 hours per GB
• Netflix HD (1080p): ~3 GB/hour → 20 minutes per GB
• Netflix 4K (UHD): ~7 GB/hour → 8-9 minutes per GB
• YouTube 480p: ~500 MB/hour → 2 hours per GB
• YouTube 1080p: ~1.5 GB/hour → 40 minutes per GB
• Zoom video call: ~600-900 MB/hour → 1-1.7 hours per GB

Cloud Storage Allocations

Free cloud storage tiers (gigabytes):

Consumer cloud services:

• Google Drive: 15 GB free (shared with Gmail and Google Photos)
• Microsoft OneDrive: 5 GB free
• Apple iCloud: 5 GB free
• Dropbox: 2 GB free (expandable with referrals)
• Amazon Photos: 5 GB free (unlimited photo storage for Prime members)
• MEGA: 20 GB free (with generous free trial bonuses)

What fits in 15 GB (Google Drive free tier)?

• Photos: 3,000-5,000 smartphone photos
• Documents: 30,000 Word documents
• Music: 1,500 MP3 songs (320 kbps)
• Video: 3-4 full 1080p movies
• Mixed use: 2,000 photos + 500 documents + 200 songs + 1 movie

Paid upgrade tiers:

• Google One: 100 GB ($1.99/month), 200 GB ($2.99/month), 2 TB ($9.99/month)
• iCloud+: 50 GB ($0.99/month), 200 GB ($2.99/month), 2 TB ($9.99/month)
• Dropbox Plus: 2 TB ($11.99/month)
• OneDrive: 100 GB ($1.99/month), 1 TB (included with Microsoft 365 $6.99/month)

RAM (Memory) Capacities

Computer RAM measured in gigabytes (technically gibibytes):

Smartphones:

• 4 GB: Budget smartphones—basic multitasking
• 6-8 GB: Mid-range standard—smooth performance for most apps
• 12 GB: Flagship phones—heavy multitasking, gaming
• 16-18 GB: Ultra-premium devices (Samsung Galaxy S23 Ultra, gaming phones)

Laptops:

• 4 GB: Minimum usable (Chromebooks, budget laptops)—limited multitasking
• 8 GB: Consumer standard—comfortable for web browsing, office work, light photo editing
• 16 GB: Professional standard—video editing, programming, heavy multitasking
• 32 GB: High-end professional—4K video editing, 3D rendering, virtual machines
• 64 GB: Workstation-class—scientific computing, large datasets, extreme workloads

Desktop PCs:

• 8 GB: Budget gaming/basic use—minimum for Windows 11
• 16 GB: Gaming/enthusiast standard—comfortable for modern games and multitasking
• 32 GB: Content creator standard—video editing, streaming, heavy production work
• 64 GB: Professional workstation—3D animation, software development, data science
• 128 GB+: Server/extreme workstation—virtualization, massive datasets, rendering farms

Servers and workstations:

• 128-256 GB: Small business servers
• 512 GB-1 TB: Enterprise servers, database servers
• 2-4 TB: High-performance computing clusters, large-scale virtualization

Game Installation Sizes

Modern video game storage requirements:

Small games (under 10 GB):

• Indie games: 2-8 GB (Hollow Knight: 9 GB, Celeste: 1.2 GB, Stardew Valley: 500 MB)
• Older AAA titles: 5-15 GB (Half-Life 2: 6.5 GB, Portal 2: 8 GB)

Medium games (10-50 GB):

• Most modern games: 20-40 GB
• Examples: Elden Ring (60 GB), Dark Souls 3 (25 GB), The Witcher 3 (50 GB)

Large games (50-100 GB):

• AAA open-world games: 50-80 GB
• Examples: Red Dead Redemption 2 (150 GB), Cyberpunk 2077 (70 GB), GTA V (94 GB)

Massive games (100+ GB):

• Call of Duty: Modern Warfare II: ~150 GB (with Warzone 2.0)
• Microsoft Flight Simulator: ~150 GB (with all updates)
• Destiny 2: ~100-120 GB
• ARK: Survival Evolved: ~250+ GB (with all DLC)

Why so large?

• 4K textures: High-resolution graphics assets (10-50 GB)
• Uncompressed audio: Multi-language voice acting (5-20 GB)
• Cinematics: Pre-rendered cutscenes in 4K (10-30 GB)
• Open world data: Massive game worlds with detailed environments

Storage impact:

• 500 GB SSD: Holds 3-5 modern AAA games comfortably
• 1 TB SSD: Holds 7-10 modern AAA games
• 2 TB SSD: Holds 15-20 modern AAA games

Common Uses

Storage Device Capacity

Capacity of hard disk drives (HDDs), solid-state drives (SSDs), USB flash drives, and memory cards.

Why gigabytes are the standard unit:

• Right size scale: Most consumer storage devices are 64 GB to 2 TB (2,000 GB)
• Marketing clarity: Easy to compare (256 GB vs. 512 GB vs. 1 TB)
• Universal understanding: Consumers understand "more GB = more storage"

Labeling conventions:

• Under 1,000 GB: Listed in gigabytes (128 GB, 256 GB, 512 GB)
• 1,000 GB and above: Listed in terabytes (1 TB, 2 TB, 4 TB)
• Decimal standard: All manufacturers use GB = 1 billion bytes exactly

Shopping considerations:

• Operating system overhead: Formatted capacity slightly less than advertised (file system metadata)
• Windows calculation: Shows capacity in GiB but labels as "GB" (appears 7% smaller)
• Price per GB: Compare costs (e.g., 512 GB SSD at $50 = $0.098/GB vs. 1 TB SSD at $80 = $0.080/GB)

Large File Sizes

Size of large files like high-definition movies, software applications, operating systems, and game installations.

Digital media distribution:

• Streaming services: Netflix, Disney+, Amazon Prime download options (2-10 GB per HD movie)
• Game digital distribution: Steam, Epic Games Store, PlayStation Store, Xbox Store (20-150 GB per game)
• Software downloads: Adobe Creative Cloud, Microsoft Office, professional apps (1-5 GB each)

File management implications:

• Download time: 50 GB game at 100 Mbps = ~67 minutes (12.5 MB/s × 4,096 seconds)
• Storage planning: Must ensure sufficient free space for installations
• Backup considerations: Large files require external drives or cloud backup plans

RAM Capacity Specifications

Measuring Random Access Memory (RAM) capacity (though gibibyte, GiB, is technically more precise and often used by OS reporting).

RAM specifications:

• Marketing: Advertised as "GB" (e.g., "16 GB DDR4 RAM")
• Technical reality: Actually measured in GiB (16 GiB = 17.18 GB)
• Module sizes: Always binary powers (4 GB, 8 GB, 16 GB, 32 GB per module)

Why binary matters for RAM:

• Memory addressing: CPUs use binary addresses (2ⁿ)
• Physical chips: Organized in binary capacities (512 Mbit, 1 Gbit, 2 Gbit chips)
• Standard modules: 8 GB module = 8 × 1,073,741,824 bytes = 8 GiB (not 8 × 1 billion bytes)

Operating system reporting:

• Windows: Shows RAM in "GB" but calculates in GiB (16,384 MB = 16 GiB shown as "16.0 GB")
• macOS: Shows RAM in GB (decimal) since OS X 10.6
• Linux: Increasingly uses GiB notation properly

Mobile Data Plans

Quantifying data usage in mobile data plans or internet bandwidth caps.

Plan structures:

• Prepaid plans: 5 GB, 10 GB, 20 GB, 40 GB monthly allotments
• Postpaid plans: Tiered (3 GB/10 GB/30 GB) or unlimited (throttled after 50-75 GB)
• Shared family plans: 20-100 GB shared across multiple lines
• Overage charges: $10-$15 per additional GB (or throttled to 128 kbps)

Tracking usage:

• Carrier apps: Real-time GB usage monitoring
• Phone settings: Built-in data usage trackers (iOS Settings → Cellular, Android Settings → Network & Internet)
• Warnings: Notifications at 75%, 90%, 100% of plan limit

International roaming:

• Expensive GB rates: $5-$20 per GB in some regions
• Roaming passes: Daily unlimited (e.g., T-Mobile $5/day, AT&T $10/day)

Cloud Storage and Backup

Cloud storage service allocations and usage.

Consumer backup workflows:

• Photo backup: Google Photos (unlimited compressed or 15 GB high-quality), iCloud Photos (5 GB free tier)
• Document sync: Dropbox, OneDrive, Google Drive for cross-device access
• Full system backup: Time Machine to external drive, Windows Backup, cloud backup services (Backblaze unlimited for $70/year)

Business cloud storage:

• Google Workspace: 30 GB per user (Business Starter), 2 TB per user (Business Standard)
• Microsoft 365 Business: 1 TB OneDrive per user
• Dropbox Business: 5 TB minimum (3+ users)

Bandwidth considerations:

• Initial upload: 500 GB to cloud at 10 Mbps upload = ~5 days continuous
• Incremental backups: Only changed files, typically MB-few GB daily

Conversion Guide

Converting Gigabytes (GB) to Megabytes (MB)

Method: Multiply by 1,000

• 1 GB = 1,000 MB (exactly, by SI definition)
• 5 GB = 5,000 MB
• 50 GB = 50,000 MB
• 500 GB = 500,000 MB

Common conversions:

• 0.5 GB = 500 MB (half gigabyte)
• 0.1 GB = 100 MB
• 0.01 GB = 10 MB
• 0.001 GB = 1 MB

Reverse conversion (MB to GB): Divide by 1,000

• 5,000 MB = 5 GB
• 250 MB = 0.25 GB
• 100 MB = 0.1 GB

Converting Gigabytes (GB) to Terabytes (TB)

Method: Divide by 1,000

• 1,000 GB = 1 TB (exactly)
• 500 GB = 0.5 TB (half terabyte)
• 250 GB = 0.25 TB (quarter terabyte)
• 100 GB = 0.1 TB

Common storage device conversions:

• 128 GB = 0.128 TB
• 256 GB = 0.256 TB
• 512 GB = 0.512 TB
• 2,000 GB = 2 TB

Reverse conversion (TB to GB): Multiply by 1,000

• 1 TB = 1,000 GB
• 2 TB = 2,000 GB
• 4 TB = 4,000 GB

Converting Gigabytes (GB) to Gibibytes (GiB)

Method: Multiply by 0.9313 (or divide by 1.074)

• 1 GB = 0.9313 GiB (approximately)
• 100 GB = 93.13 GiB
• 500 GB = 465.66 GiB
• 1,000 GB (1 TB) = 931.32 GiB

Exact formula:

• GiB = GB × (1,000,000,000 ÷ 1,073,741,824)
• GiB = GB × 0.93132257...

Reverse conversion (GiB to GB): Multiply by 1.074

• 1 GiB = 1.074 GB (approximately)
• 100 GiB = 107.4 GB
• 500 GiB = 536.9 GB
• 931.32 GiB = 1,000 GB (1 TB)

Why this matters:

• "Missing storage": 1 TB drive shows as 931 GB in Windows (actually 931 GiB mislabeled)
• RAM specifications: "16 GB RAM" is actually 16 GiB = 17.18 GB

Converting Gigabytes (GB) to Gigabits (Gb)

Method: Multiply by 8 (since 1 byte = 8 bits)

• 1 GB = 8 Gb
• 10 GB = 80 Gb
• 100 GB = 800 Gb

Why this matters:

• Internet speeds: Advertised in gigabits per second (Gbps), not gigabytes per second (GB/s)
• Download time calculation: 1 Gbps connection downloads at ~125 MB/s (0.125 GB/s), not 1 GB/s

Reverse conversion (Gb to GB): Divide by 8

• 8 Gb = 1 GB
• 80 Gb = 10 GB
• 1 Gbps = 125 MB/s = 0.125 GB/s

Common Conversion Mistakes

1. Mistake: Confusing GB (Gigabyte) with Gb (Gigabit)

The error: Mixing up gigabytes and gigabits when calculating download speeds.

Reality:

• 1 gigabyte (GB) = 8 gigabits (Gb)
• Internet speeds: Advertised in gigabits per second (Gbps), NOT gigabytes per second
• File sizes: Measured in gigabytes (GB), NOT gigabits

Real-world example:

• "1 Gbps fiber internet" does NOT download at 1 GB per second
• Actual download speed: 1 Gbps ÷ 8 = 125 MB/s (megabytes per second) = 0.125 GB/s
• To download 10 GB: 10 GB ÷ 0.125 GB/s = 80 seconds (not 10 seconds!)

Correct calculations:

• 100 Mbps connection: 100 ÷ 8 = 12.5 MB/s = 0.0125 GB/s
• 1 Gbps connection: 1,000 ÷ 8 = 125 MB/s = 0.125 GB/s
• 10 Gbps connection: 10,000 ÷ 8 = 1,250 MB/s = 1.25 GB/s

Remember: Lowercase 'b' = bit, Uppercase 'B' = Byte

2. Mistake: Thinking GB and GiB Are the Same

The error: Assuming 1 GB = 1 GiB, leading to confusion about "missing storage."

Reality:

• 1 GB (gigabyte) = 1,000,000,000 bytes (decimal, 10⁹)
• 1 GiB (gibibyte) = 1,073,741,824 bytes (binary, 2³⁰)
• 1 GiB is 7.37% larger than 1 GB

Why your drive appears smaller:

• Manufacturer: 500 GB = 500,000,000,000 bytes
• Windows: Divides by 1,073,741,824 (GiB) = 465.66 GiB
• Windows displays: "465 GB" (actually 465 GiB mislabeled)
• Result: Looks like you "lost" 35 GB, but you didn't—it's just unit conversion

Conversion:

• 100 GB = 93.13 GiB (6.87 GB "missing")
• 500 GB = 465.66 GiB (34.34 GB "missing")
• 1 TB (1,000 GB) = 931.32 GiB (68.68 GB "missing")

This is NOT false advertising—it's just two different unit systems measuring the same bytes.

3. Mistake: Using 1,024 Instead of 1,000 for GB Conversions

The error: Converting GB to MB using 1,024 instead of 1,000.

Reality:

• Correct (GB = decimal): 1 GB = 1,000 MB (exactly)
• Wrong (mixing GB with binary): 1 GB ≠ 1,024 MB
• Binary prefix: 1 GiB = 1,024 MiB (correct for gibibytes, NOT gigabytes)

Example error:

• Wrong: 5 GB × 1,024 = 5,120 MB ❌
• Right: 5 GB × 1,000 = 5,000 MB ✓

When to use 1,024:

• Converting GiB to MiB: 1 GiB = 1,024 MiB ✓
• Converting GB to MB: 1 GB = 1,000 MB ✓ (NOT 1,024)

Remember: GB uses decimal (1,000), GiB uses binary (1,024)

4. Mistake: Assuming Linear Pricing for Storage

The error: Thinking 2× storage = 2× price (doubling capacity doubles cost).

Reality: Storage has economies of scale—larger capacities often have better price per GB.

Example (SSDs):

• 256 GB SSD: $30 → $0.117 per GB
• 512 GB SSD: $50 → $0.098 per GB (16% cheaper per GB)
• 1 TB SSD: $80 → $0.080 per GB (32% cheaper per GB than 256 GB)

Why this happens:

• Fixed costs: Controller, circuit board, packaging same regardless of capacity
• NAND chip costs: Larger chips cheaper per GB due to manufacturing efficiency

Shopping tip: Often better value to buy 2× capacity even if you don't need it immediately—costs only ~50-70% more, not 100% more.

5. Mistake: Forgetting About Formatted Capacity

The error: Expecting full advertised capacity to be usable after formatting.

Reality:

• File system overhead: File system metadata (partition tables, file allocation tables) uses 1-2% of capacity
• OS reserved space: Windows reserves space for System Restore, hibernation file

Example:

• 500 GB drive purchased
• Manufacturer: 500,000,000,000 bytes (exactly 500 GB)
• After formatting (NTFS): ~498 GB usable (2 GB for file system)
• Windows shows: 465 GB (calculated in GiB, mislabeled as GB)
• Final usable: ~463-464 GB shown in Windows

Total "loss": ~7-8% appears missing (combination of GiB calculation + file system overhead)

Not a problem, just reality—this is normal and expected for all drives.

6. Mistake: Confusing Data Transfer with Data Storage

The error: Thinking a "1 GB data plan" means you can download 1 GB of files.

Reality:

• Data plan GB: Measures all network traffic (downloads + uploads + overhead)
• File size GB: Only the actual file payload

Hidden data usage:

• HTTP overhead: Headers, handshaking (~10-15% overhead)
• TCP/IP overhead: Network protocol overhead (~5-10%)
• Ads and tracking: Webpages include ads, analytics (can double data usage)
• Failed downloads: Partial downloads count toward usage even if incomplete

Example:

• Download 1 GB file: Actually uses ~1.1-1.2 GB from data plan
• Stream 1 hour Netflix (claims 1 GB): Actually uses ~1.15 GB including overhead
• Browse web "50 MB": May use 75-100 MB including ads, images, autoplay videos

Data-saving tip: Use data compression (Chrome Data Saver, Opera Turbo) or ad blockers to reduce overhead.