Ell to Millimeter Converter

Convert ells to millimeters with our free online length converter.

Quick Answer

1 Ell = 1143 millimeters

Formula: Ell × conversion factor = Millimeter

Use the calculator below for instant, accurate conversions.

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All conversion formulas on UnitsConverter.io have been verified against NIST (National Institute of Standards and Technology) guidelines and international SI standards. Our calculations are accurate to 10 decimal places for standard conversions and use arbitrary precision arithmetic for astronomical units.

Last verified: February 2026Reviewed by: Sam Mathew, Software Engineer

Ell to Millimeter Calculator

How to Use the Ell to Millimeter Calculator:

  1. Enter the value you want to convert in the 'From' field (Ell).
  2. The converted value in Millimeter will appear automatically in the 'To' field.
  3. Use the dropdown menus to select different units within the Length category.
  4. Click the swap button (⇌) to reverse the conversion direction.
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How to Convert Ell to Millimeter: Step-by-Step Guide

Converting Ell to Millimeter involves multiplying the value by a specific conversion factor, as shown in the formula below.

Formula:

1 Ell = 1143 millimeters

Example Calculation:

Convert 10 ells: 10 × 1143 = 1.1430e+4 millimeters

Disclaimer: For Reference Only

These conversion results are provided for informational purposes only. While we strive for accuracy, we make no guarantees regarding the precision of these results, especially for conversions involving extremely large or small numbers which may be subject to the inherent limitations of standard computer floating-point arithmetic.

Not for professional use. Results should be verified before use in any critical application. View our Terms of Service for more information.

What is a Ell and a Millimeter?

The Ell is an historical unit of length, primarily used for measuring cloth and textiles. Its exact length varied considerably depending on the region, country, and time period, making it a non-standardized unit overall, though often legally defined within specific jurisdictions.

It is generally understood to have originated from the length of the arm or forearm, similar to the cubit. The name itself derives from the Proto-Germanic word *alinō, meaning "forearm".

Common historical values demonstrate this variability:

  • English Ell: Traditionally 45 inches (1.25 yards, exactly 1.143 meters). This was the most common ell in England, particularly for measuring imported Flemish cloth.
  • Scottish Ell: Approximately 37.06 inches (about 0.941 meters), based on the standard Scottish inch.
  • Flemish (or Brabant) Ell: Approximately 27 inches (about 0.686 meters). Widely used in the Low Countries, a major center for textile production.
  • French Ell (Aune): Varied, but often around 46.77 inches (about 1.188 meters) in Paris. The aune itself had different lengths in different French regions.
  • Polish Ell (Łokieć): Approximately 22.7 inches (about 0.576 meters).
  • Swedish Ell (Aln): Approximately 23.3 inches (about 0.593 meters).

The millimeter (symbol: mm) is a unit of length in the metric system equal to one-thousandth of a meter (1/1,000 m) or one-tenth of a centimeter (1/10 cm). It is used for precise measurements in engineering, manufacturing, and everyday applications.

Key relationships:

  • 1 millimeter = 0.001 meters (m)
  • 1 millimeter = 0.1 centimeters (cm)
  • 10 millimeters = 1 centimeter
  • 1,000 millimeters = 1 meter
  • 1 millimeter ≈ 0.03937 inches (about 1/25th inch)
  • 25.4 millimeters = 1 inch (exactly)

The prefix "milli-":

  • From Latin "mille" meaning "thousand"
  • SI prefix denoting 10⁻³ (one-thousandth)
  • Also used in: milligram (mg), milliliter (mL), millisecond (ms)

Visual perspective (how big is it?):

  • 1 mm = Thickness of a credit card
  • 2 mm = Thickness of a US dime
  • 5 mm = Thickness of a pencil lead (mechanical)
  • 10 mm = Width of an adult fingernail
  • 25.4 mm = Exactly one inch

Convert between length units: mm converter

Note: The Ell is part of the imperial/US customary system, primarily used in the US, UK, and Canada for everyday measurements. The Millimeter belongs to the metric (SI) system.

History of the Ell and Millimeter

The ell was a fundamental unit for the textile trade across Europe, flourishing from the medieval period through the early modern era and into the 19th century. Its origins likely lie in anthropomorphic measurements related to the arm, similar to the cubit.

The lack of a universal standard led to numerous regional variations. Different cities, guilds, or nations established their own "standard" ell, often physically represented by a metal rod kept by authorities. This variation could sometimes be a source of trade disputes but also reflected local manufacturing and trade practices.

The English ell of 45 inches (longer than the standard English yard of 36 inches) became particularly well-established, possibly to account for shrinkage or to provide a customary "bonus" measure when selling cloth.

With the rise of standardized measurement systems like the Imperial system (promoting the yard) and especially the Metric system (introducing the meter), the ell gradually became obsolete during the 18th and 19th centuries. Legal reforms in many countries formally abolished it in favor of metric units.

  • Metric System Origins: The millimeter was defined as a subunit of the meter when the metric system was established in France during the late 18th century (1790s). As measurement standardization progressed, the need for decimal subdivisions of the meter became clear.

  • Industrial Revolution: The millimeter became essential during the 19th century Industrial Revolution as:

    • Precision machining required fine tolerances
    • Interchangeable parts manufacturing emerged
    • Engineering drawings needed standard units
    • Technical specifications became international
  • Engineering Adoption: By the mid-19th century, engineers and machinists worldwide adopted millimeters as the standard for:

    • Machine tool specifications
    • Tolerance requirements (±0.1 mm common)
    • Technical drawing dimensions
    • Quality control measurements
  • Scientific Standardization: The millimeter became standard in scientific research for:

    • Laboratory equipment calibration
    • Microscopy measurements
    • Specimen documentation
    • Experimental apparatus dimensions
  • SI Formalization: When the International System of Units (SI) was established in 1960, the millimeter was confirmed as an official subdivision of the meter, forming part of the coherent decimal system.

  • Modern Manufacturing: The 20th century saw millimeters become universal in:

    • Automotive engineering specifications
    • Electronics manufacturing (PCB design)
    • Aerospace tolerances
    • Medical device specifications
    • Consumer product dimensions
  • Global Standard: Today, millimeters are the primary unit for precision measurements in virtually every country except the United States (which uses both mm and inches). Even in the US, many technical fields have adopted millimeters as standard.

Common Uses and Applications: ells vs millimeters

Explore the typical applications for both Ell (imperial/US) and Millimeter (metric) to understand their common contexts.

Common Uses for ells

The ell is now obsolete but was historically crucial for:

  • Textile Trade: Its primary and defining use was measuring and selling lengths of cloth (wool, linen, silk, etc.). Cloth was often priced and sold "by the ell".
  • Tailoring and Dressmaking: Used by artisans creating garments.
  • Mercantile Records: Appears frequently in historical merchant accounts, inventories, customs documents, and trade records. Understanding the local ell is vital for interpreting these economic historical sources.
  • Land Measurement (Rarely): In some specific, localized contexts, an ell might have been used for land, but this was uncommon compared to units like the rod or chain.
  • Literature and Culture: Referenced in historical texts, literature, and idioms (e.g., "Give him an inch, and he'll take an ell").

When to Use millimeters

The millimeter is the standard unit for precise measurements across multiple fields:

Engineering & Machining

Precise measurement requirements for manufacturing, quality control, and technical specifications. Essential for maintaining tolerances in mechanical parts.

Why millimeters in engineering:

  • Decimal system (easy calculations)
  • International standard (ISO)
  • Suitable precision range
  • Compatible with CNC machinery
  • Standard drawing units

Applications:

  • Machine tool specifications
  • Part tolerances (±0.05 mm common)
  • Technical drawing dimensions
  • CAD/CAM software units
  • Quality inspection reports

Convert for technical work: mm to inches | mm to cm


Technical Design & Drafting

Standard measurement unit for architectural, mechanical, and technical drawings worldwide.

Drawing Standards:

  • ISO standards use millimeters
  • Engineering drawings in mm
  • Architecture plans (many countries)
  • Product design specifications
  • Patent drawings (international)

Why mm for drawings:

  • Eliminates fractions (unlike inches)
  • Scales easily (1:10, 1:100, etc.)
  • International communication
  • CAD software standard

Electronics & PCB Design

Measuring component sizes, trace widths, and circuit board dimensions in electronic manufacturing.

PCB Design:

  • Trace width: 0.25-1 mm
  • Component footprints: mm specifications
  • Hole diameters: 0.6-1.2 mm
  • Board thickness: 1.6 mm standard
  • Component spacing: mm grid

Component Specs:

  • All modern ICs specified in mm
  • Resistor/capacitor sizes (mm codes)
  • Connector dimensions
  • Display module sizes

Meteorology & Climate

Measuring rainfall amounts with precision, essential for weather forecasting, agriculture, and climate research.

Rain Gauges:

  • Standard measurement unit worldwide
  • Collected in graduated cylinders (mm scale)
  • Automated weather stations use mm
  • Historical records in mm
  • Climate data standardized

Importance:

  • Drought assessment
  • Flood prediction
  • Agricultural planning
  • Water resource management
  • Climate change tracking

Use our mm converter for scientific calculations.


Manufacturing & Quality Control

Inspecting product dimensions and ensuring parts meet specifications within required tolerances.

QC Measurements:

  • Caliper readings in mm
  • Micrometer measurements
  • Coordinate measuring machines (CMM)
  • Surface profile measurements
  • Dimensional inspection reports

Industries:

  • Automotive parts
  • Aerospace components
  • Medical devices
  • Consumer electronics
  • Precision instruments

Jewelry & Watchmaking

Specifying sizes of gems, watch cases, and jewelry components with precision.

Why jewelers use mm:

  • International gem standard
  • Precise size communication
  • Watch industry standard
  • Setting specifications
  • Customer communication

Measurements:

  • Gemstone dimensions
  • Ring widths and thicknesses
  • Watch case diameters
  • Bracelet link sizes
  • Clasp dimensions

Medical Measurements

Documenting precise measurements in diagnostics, surgery planning, and treatment monitoring.

Clinical Uses:

  • Imaging measurements (CT, MRI, X-ray)
  • Tumor size tracking
  • Surgical planning
  • Needle specifications
  • Medical device dimensions

Why mm in medicine:

  • International standard
  • Appropriate precision
  • Imaging system default
  • Research compatibility
  • Treatment standardization

Additional Unit Information

About Ell (ell)

How long is an Ell?

There is no single fixed length for the ell; it varied significantly by location and time. Some key examples include:

  • English Ell: 45 inches (1.143 m)
  • Scottish Ell: ~37 inches (~0.94 m)
  • Flemish Ell: ~27 inches (~0.69 m)
  • French Aune (Ell): ~47 inches (~1.19 m) Always check the context (region and era) when encountering a measurement in ells. The English ell of 45 inches is often assumed in English-language historical contexts unless otherwise specified.

How does the Ell compare to a Yard?

The English ell (45 inches) is exactly 1.25 times longer than the standard yard (36 inches). However, other ells could be shorter (like the Flemish ell) or have different relationships to the local yard equivalent.

Is the Ell related to the Elbow or Arm?

Yes, the name "ell" derives from Proto-Germanic *alinō ("forearm"), cognate with Latin ulna and Greek ōlénē, all referring to the forearm or elbow. This strongly suggests an origin based on the length of the human arm, similar to the cubit. However, the standardized lengths adopted for trade were often considerably longer than a literal forearm.

Why did the Ell length vary so much?

The variation stemmed from:

  • Lack of Universal Standards: Before the metric system, measurement standards were highly localized.
  • Regional Customs: Different areas developed their own traditional lengths based on local needs and practices.
  • Trade Protectionism: Sometimes, variations were maintained deliberately by guilds or cities.
  • Evolution Over Time: The definition could change even within the same region over centuries.

Is the Ell an SI unit?

No, the ell is not part of the International System of Units (SI). It is an historical, customary unit belonging to various pre-metric systems. The corresponding SI unit for length is the meter (m).

Is the Ell still used today?

No, the ell is obsolete and is not used for any standard commercial, scientific, or practical measurements today. Its use was superseded primarily by the yard (in Imperial/US customary systems) and the meter (in the metric system). Its relevance is now purely historical.

About Millimeter (mm)

How many millimeters are in a centimeter?

There are exactly 10 millimeters (mm) in 1 centimeter (cm).

Conversion:

  • 1 cm = 10 mm
  • To convert cm to mm: multiply by 10
  • To convert mm to cm: divide by 10

Examples:

  • 5 cm = 50 mm
  • 2.5 cm = 25 mm
  • 75 mm = 7.5 cm

Memory aid: "Centi-" means 1/100 meter, "milli-" means 1/1,000 meter, so 10 mm = 1 cm.

Use our cm to mm converter for instant conversions.

How many millimeters are in a meter?

There are exactly 1,000 millimeters (mm) in 1 meter (m).

Conversion:

  • 1 m = 1,000 mm
  • To convert m to mm: multiply by 1,000
  • To convert mm to m: divide by 1,000

Examples:

  • 0.5 m = 500 mm
  • 1.5 m = 1,500 mm
  • 2,750 mm = 2.75 m

Remember: "Milli-" means one-thousandth, so it takes 1,000 mm to make 1 meter.

Convert: mm to meters | meters to mm

What does 'milli' mean in millimeter?

The prefix 'milli-' denotes one-thousandth (1/1,000).

Meaning:

  • Comes from Latin "mille" meaning "thousand"
  • In metric system: milli- = 10⁻³ = 1/1,000
  • 1 millimeter = 1/1,000 of a meter = 0.001 m

Other "milli-" units:

  • Milligram (mg) = 1/1,000 gram
  • Milliliter (mL) = 1/1,000 liter
  • Millisecond (ms) = 1/1,000 second
  • Milliamp (mA) = 1/1,000 ampere

Pattern: Always divide by 1,000 to get the base unit.

How thick is 1 millimeter?

1 millimeter is very thin - about the thickness of:

Common objects:

  • Credit card: 0.76 mm (slightly thinner)
  • US dime: 1.35 mm (slightly thicker)
  • 10 sheets of paper: ~1 mm
  • Paperclip wire: ~1 mm diameter
  • Mechanical pencil lead (0.7mm): Slightly thinner

Visual comparison:

  • Thinner than a US penny (1.55 mm)
  • About 1/25th of an inch (0.04 inches)
  • 10 millimeters = 1 cm = width of fingernail

To visualize: Look at the edge of a credit card - that's less than 1 mm.

How many mm in an inch?

1 inch = 25.4 millimeters exactly (by international agreement).

This is a defined conversion (not an approximation):

  • 1 inch ≡ 25.4 mm (exact)
  • 1 mm = 1/25.4 inch ≈ 0.03937 inches

Common conversions:

  • 1 inch = 25.4 mm
  • 2 inches = 50.8 mm
  • 3 inches = 76.2 mm
  • 4 inches = 101.6 mm
  • 12 inches (1 foot) = 304.8 mm

Reverse examples:

  • 10 mm ≈ 0.394 inches
  • 25 mm ≈ 0.984 inches (almost 1 inch)
  • 50 mm ≈ 1.969 inches (almost 2 inches)

Memory trick: 25 mm is almost 1 inch (close enough for quick estimates).

Use our inch to mm converter for precise conversions.

What is 10mm in real life?

10 millimeters = 1 centimeter - about the width of an adult fingernail.

Common 10mm objects:

  • Fingernail width (adult index finger)
  • AA battery diameter: 14 mm (close)
  • Small marble: ~10-15 mm diameter
  • M10 bolt diameter: 10 mm
  • Thick cardboard: ~10 mm

Comparisons:

  • Just under 0.4 inches (0.394 inches exactly)
  • Thickness of 100 sheets of paper
  • About 3/8 inch (slightly larger)

In measurements:

  • Camera/phone thickness: Often 7-10 mm
  • Watch case thickness: Often 10-12 mm
  • Pencil diameter: ~7-8 mm (10mm would be thick)

How do you read a metric ruler?

Metric rulers are divided into centimeters (cm) and millimeters (mm):

Reading steps:

  1. Large numbers: Centimeters (0, 1, 2, 3...)
  2. Long lines: Each centimeter mark
  3. Short lines: Millimeters (10 per cm)
  4. Count: From zero to your measurement point

Example reading:

  • Between 3 and 4 cm, at the 7th small line = 3.7 cm or 37 mm
  • At the 15th cm mark = 15 cm or 150 mm

Tips:

  • 10 small marks = 1 cm
  • Each small mark = 1 mm
  • Halfway between cm marks = 5 mm
  • Read to nearest 0.5 mm for precision

Reporting:

  • Small objects: Use mm (e.g., "15 mm")
  • Larger objects: Use cm (e.g., "15.5 cm")
  • Both are correct, choose clearer one

What tools measure millimeters?

Many tools measure in millimeters:

Hand Tools:

  • Metric ruler: Basic measurement to 1 mm
  • Metric tape measure: Construction/carpentry
  • Caliper: Precision to 0.01 mm (digital/vernier)
  • Micrometer: Very precise, to 0.001 mm
  • Depth gauge: Measuring depths and heights

Digital Tools:

  • Digital caliper: Easy reading, 0.01 mm precision
  • Laser distance meter: Millimeter accuracy
  • Height gauge: Vertical measurements
  • Coordinate measuring machine (CMM): Industrial precision

Specialized Tools:

  • Feeler gauge: Thin strips in mm thicknesses
  • Thread gauge: Checking thread pitch (mm)
  • Bore gauge: Internal diameter measurement
  • Pin gauge: Precision hole measurement

Which to use:

  • Ruler: General purpose (±0.5 mm)
  • Caliper: Precision work (±0.01 mm)
  • Micrometer: Very tight tolerances (±0.001 mm)

Is mm smaller than cm?

Yes, millimeters (mm) are smaller than centimeters (cm).

Relationship:

  • 1 cm = 10 mm
  • 1 mm = 0.1 cm
  • Millimeter is 10 times smaller than centimeter

Scale comparison:

  • Largest: meter (m)
  • Middle: centimeter (cm) = 1/100 m
  • Smallest: millimeter (mm) = 1/1,000 m

Visual:

  • Width of fingernail: 1 cm = 10 mm
  • Thickness of dime: 1.35 mm (can't easily express in cm)

When to use each:

  • Use mm: Small, precise measurements (< 100 mm)
  • Use cm: Medium measurements (1-100 cm)
  • Use m: Large measurements (> 1 meter)

Example:

  • Pencil length: 19 cm or 190 mm (19 cm clearer)
  • Wire diameter: 2 mm (not 0.2 cm - awkward)

How much rain is 1mm?

1 millimeter of rain means 1 mm depth of water would cover a flat surface if none drained away.

What it means:

  • 1 mm rain = 1 liter per square meter of water
  • Light drizzle might produce 1-2 mm/hour
  • Barely enough to wet the ground thoroughly

Rain intensity scale:

  • Trace-1 mm: Very light drizzle
  • 1-2 mm: Light rain
  • 2-5 mm: Light to moderate rain
  • 5-10 mm: Moderate rain
  • 10-20 mm: Heavy rain
  • 20-50 mm: Very heavy rain
  • >50 mm: Extreme rainfall (per hour)

Practical impact:

  • 1 mm: Barely wets surfaces
  • 10 mm: Significant watering
  • 25 mm: Heavy rain event
  • 100 mm: Major storm (in 24 hours)

Measurement:

  • Rain gauge collects water
  • Depth measured in mm
  • Standard worldwide for weather reporting

Conversion Table: Ell to Millimeter

Ell (ell)Millimeter (mm)
0.5571.5
11,143
1.51,714.5
22,286
55,715
1011,430
2528,575
5057,150
100114,300
250285,750
500571,500
1,0001,143,000

People Also Ask

How do I convert Ell to Millimeter?

To convert Ell to Millimeter, enter the value in Ell in the calculator above. The conversion will happen automatically. Use our free online converter for instant and accurate results. You can also visit our length converter page to convert between other units in this category.

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What is the conversion factor from Ell to Millimeter?

The conversion factor depends on the specific relationship between Ell and Millimeter. You can find the exact conversion formula and factor on this page. Our calculator handles all calculations automatically. See the conversion table above for common values.

Can I convert Millimeter back to Ell?

Yes! You can easily convert Millimeter back to Ell by using the swap button (⇌) in the calculator above, or by visiting our Millimeter to Ell converter page. You can also explore other length conversions on our category page.

Learn more →

What are common uses for Ell and Millimeter?

Ell and Millimeter are both standard units used in length measurements. They are commonly used in various applications including engineering, construction, cooking, and scientific research. Browse our length converter for more conversion options.

For more length conversion questions, visit our FAQ page or explore our conversion guides.

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Verified Against Authority Standards

All conversion formulas have been verified against international standards and authoritative sources to ensure maximum accuracy and reliability.

NIST Guide for the Use of SI

National Institute of Standards and TechnologyOfficial US standards for length measurements

SI Brochure

Bureau International des Poids et MesuresInternational System of Units official documentation

Last verified: February 19, 2026