Mile per hour (mph) - Unit Information & Conversion

Quick Answer: What is Miles per Hour?

Miles per hour (mph) is a unit of speed meaning the number of miles traveled in one hour. At 60 mph, you travel exactly one mile every minute. Miles per hour is the standard speed measurement in the US for speed limits (residential 25 mph, highway 65-75 mph, school zones 15-20 mph), vehicle speedometers, weather reports (wind speed, hurricane categories), and sports (baseball pitch speeds 90-100 mph, NASCAR 200+ mph). It's the primary speed unit used by 330+ million Americans and 67+ million Britons daily.

Miles per Hour Comparison Table

From	To	Relationship
1 mph	km/h	1.60934 km/h
1 mph	m/s	0.44704 m/s
1 mph	ft/s	1.46667 ft/s
1 mph	knots	0.868976 knots
1 km/h	mph	0.621371 mph
1 m/s	mph	2.23694 mph
60 mph	miles per minute	1 mile/min
60 mph	feet per second	88 ft/s

Definition

Miles per hour (symbol: mph, MPH, or mi/h) is a unit of speed expressing the number of statute miles traveled in one hour.

Formula: Speed (mph) = Distance (miles) ÷ Time (hours)

Mathematical relationships:

• 1 mph = 1.60934 km/h (kilometers per hour)
• 1 mph = 0.44704 m/s (meters per second)
• 1 mph = 1.46667 ft/s (feet per second)
• 1 mph = 0.868976 knots

Key mental math: At 60 mph:

• You travel exactly 1 mile per minute
• You travel 88 feet per second
• You cover about 97 km/h

Why Miles per Hour Works

Intuitive scaling: The numbers align well with human driving speeds:

• Walking: 3-4 mph
• Residential driving: 25-35 mph
• Highway cruising: 60-70 mph
• Fast driving: 80-90 mph

Easy mental math at 60 mph: When driving 60 mph, distance and time calculations become trivial:

• 30 miles away = 30 minutes
• 90 miles away = 90 minutes (1.5 hours)
• 120 miles away = 120 minutes (2 hours)

This makes 60 mph a natural "reference speed" for American drivers.

History

Early 19th Century: Railway Origins

1820s-1830s Railway Boom: The first practical use of "miles per hour" appeared in British railway timetables in the 1820s and 1830s. Steam locomotives needed a standardized way to express speed.

Early Rail Speeds:

• 1825: Stockton & Darlington Railway averaged 15 mph (first passenger railway)
• 1830: Liverpool & Manchester Railway achieved 30 mph
• 1848: Railway speed records exceeded 60 mph

Why mph? Britain used statute miles for road distances, making mph the natural choice for rail speed measurement.

Mid-19th Century: Speed Regulation

1865: The "Red Flag Act" (UK): The Locomotive Act of 1865 limited self-propelled vehicles to:

• 4 mph in open country
• 2 mph in towns
• Required a person with a red flag walking ahead

This was the first national speed limit using mph, though it severely hampered early automotive development.

1896: Repeal and Freedom: The red flag requirement was repealed, allowing vehicles up to 14 mph.

Late 19th Century: Automotive Era Begins

1890s-1900s: Early Automobiles: As automobiles emerged, mph naturally became their speed measurement since roads already used miles for distance.

Early Auto Speeds:

• 1894: First automobile race averaged 15 mph (Paris-Rouen)
• 1906: Land speed record reached 127 mph
• 1920s: Typical cars cruised at 40-50 mph

20th Century: Speed Limits and Standards

1934: First US National Speed Limit (informal): Many states adopted 55-65 mph highway limits.

1974: National Maximum Speed Law (US): Energy crisis led Congress to mandate 55 mph nationwide to conserve fuel (1974-1987).

1987-1995: Speed Limits Raised: States regained control; limits increased to 65 mph on rural interstates.

1995-Present: Modern Speed Limits: Federal speed limit repealed. States set own limits:

• Rural interstates: 70-85 mph (Texas has 85 mph zones)
• Urban interstates: 55-70 mph
• Rural highways: 55-65 mph
• Urban streets: 25-45 mph

Global Metrication: The mph Holdouts

1960s-1970s: World Shifts to km/h: Most countries adopted the metric system and switched to km/h:

• Australia: 1974
• Canada: 1977
• Ireland: 2005
• South Africa: 1976

mph Survivors: Only a few countries still use mph:

• United States: All 50 states use mph exclusively
• United Kingdom: Road signs in mph (railways and aviation use km/h or knots)
• Some Caribbean nations: Remnants of British colonial influence

Real-World Examples: What Does mph Look Like?

Walking and Running Speeds

Walking:

• Leisurely stroll: 2-3 mph
• Average walking: 3-4 mph
• Brisk walk: 4-5 mph
• Power walking: 5-6 mph (Olympic race walking: ~9 mph)

Running:

• Jogging: 4-6 mph
• Recreational running: 6-8 mph
• Moderate running: 8-10 mph
• Competitive running: 10-12 mph
• Elite marathon pace: 12-13 mph (4:40 mile pace)
• World record mile: 16.13 mph (3:43 mile, Hicham El Guerrouj)

Sprint speeds:

• High school sprinter: 15-18 mph
• College sprinter: 18-20 mph
• Usain Bolt (peak): 27.8 mph (100m world record, 2009)

Vehicle Speed Limits (US)

Urban/Residential:

• School zones: 15-20 mph (when children present)
• Residential streets: 25-35 mph
• Urban arterials: 35-45 mph
• Business districts: 25-35 mph

Rural/Highway:

• Rural two-lane roads: 45-55 mph
• State highways: 55-65 mph
• Interstate highways (urban): 55-65 mph
• Interstate highways (rural): 65-80 mph
• Texas State Highway 130: 85 mph (highest US limit)

Other Countries Using mph:

• UK motorways: 70 mph
• UK single carriageways: 60 mph
• UK urban areas: 30 mph

Driving Scenarios

City Driving:

• Parking lots: 5-15 mph
• Stop-and-go traffic: 0-20 mph average
• Normal city flow: 25-35 mph
• Busy arterials: 35-45 mph

Highway Driving:

• Entering highway: accelerating from 45 to 65 mph
• Cruising: 65-75 mph typical
• Passing: briefly 75-85 mph
• Traffic flow: varies 50-80 mph

60 mph - The Reference Speed:

• Covers exactly 1 mile per minute
• 30-minute drive = 30 miles
• 2-hour drive = 120 miles
• Makes mental calculations easy

Weather and Natural Phenomena

Wind Speed (US Weather Reports):

• Calm: 0-1 mph
• Light breeze: 4-7 mph
• Gentle breeze: 8-12 mph
• Moderate breeze: 13-18 mph
• Fresh breeze: 19-24 mph
• Strong breeze: 25-31 mph
• Moderate gale: 32-38 mph
• Fresh gale: 39-46 mph
• Strong gale: 47-54 mph
• Storm: 55-63 mph
• Violent storm: 64-72 mph
• Hurricane: 74+ mph

Hurricane Categories (Saffir-Simpson Scale):

• Category 1: 74-95 mph sustained winds
• Category 2: 96-110 mph
• Category 3: 111-129 mph (major hurricane)
• Category 4: 130-156 mph
• Category 5: 157+ mph

Tornado Wind Speeds (EF Scale estimates):

• EF0: 65-85 mph
• EF1: 86-110 mph
• EF2: 111-135 mph
• EF3: 136-165 mph
• EF4: 166-200 mph
• EF5: 200+ mph

Sports and Athletics

Baseball:

• Fastball pitch: 90-100 mph (MLB average ~93 mph)
• Record fastball: 105.1 mph (Aroldis Chapman, 2010)
• Curveball: 70-80 mph
• Changeup: 75-85 mph
• Exit velocity (batted ball): 100+ mph for home runs

Tennis:

• Serve speed (men): 100-140 mph
• Record serve: 163.7 mph (Sam Groth, 2012)
• Groundstroke: 70-90 mph

Golf:

• Driver swing speed (PGA Tour): 110-120 mph
• Ball speed off driver: 160-180 mph

Motorsports:

• NASCAR: 180-200 mph on superspeedways
• IndyCar: 220-240 mph on oval tracks
• Formula 1: 220+ mph top speed (racing speeds 150-200 mph)
• Drag racing (Top Fuel): 330+ mph

Animal Speeds

Land Animals:

• Cheetah: 70 mph (fastest land animal)
• Pronghorn antelope: 60 mph
• Springbok: 55 mph
• Greyhound: 45 mph
• Racehorse: 40-45 mph (Thoroughbred gallop)
• House cat: 30 mph (sprint)
• Human (Usain Bolt): 27.8 mph
• Elephant: 25 mph
• Squirrel: 20 mph

Birds in Flight:

• Peregrine falcon (dive): 240 mph (fastest animal)
• Golden eagle (dive): 150-200 mph
• Hummingbird: 30 mph (normal), 60 mph (dive)
• Pigeon: 50-60 mph

Common Uses

Road Transportation Standard

Speed Limits: All US road signs display mph:

• Speed Limit 25
• Speed Limit 55
• Speed Limit 70

Speedometers: All vehicles sold in the US have mph as primary scale:

• Digital displays: show mph
• Analog gauges: mph prominently displayed (km/h smaller, if present)

Traffic Enforcement:

• Speed cameras calibrated in mph
• Radar guns measure mph
• Tickets written in mph ("45 mph in a 30 mph zone")

Weather Forecasting

Wind Speed: US weather reports use mph:

• "Winds 10-15 mph"
• "Gusts up to 40 mph"
• "Sustained winds of 75 mph" (hurricane)

Severe Weather Warnings:

• High wind warning: sustained winds 40+ mph
• Hurricane watch: sustained winds 74+ mph expected
• Tornado warning: rotational winds estimated in mph

Weather Apps: US apps default to mph for wind speed.

Aviation Context (Mixed Use)

Airspeed Indicators: Pilots see:

• Knots (nautical miles per hour) - primary in aviation
• Some general aviation planes show mph

Ground Speed: GPS and flight computers often display:

• Knots for professional aviation
• mph option available for private pilots

Weather Briefings: Aviation weather uses knots, but surface winds at some small airports reported in mph.

Sports Performance Measurement

Baseball Pitch Tracking:

• MLB stadiums display pitch speed in mph on scoreboards
• "95 mph fastball"
• Scouting reports use mph

Racing:

• NASCAR: "Averaging 185 mph for the lap"
• Drag racing: "Trap speed 325 mph"
• Land speed records: measured in mph

Speed Skating, Cycling: In US competitions, sometimes reported in mph alongside metric.

Everyday Distance/Time Calculations

Trip Planning: Americans mentally calculate travel time using mph:

• "It's 180 miles, so 3 hours at 60 mph"
• "I average 70 mph on the highway, so 350 miles takes 5 hours"

Fuel Economy Relationship: MPG (miles per gallon) and mph are connected:

• Highway MPG ratings assume 55-65 mph
• Fuel economy drops significantly above 70 mph

Real Estate: Property distance to amenities:

• "20 minutes at 45 mph = about 15 miles"

Conversion Mistakes to Avoid

1. Rounding mph to km/h Incorrectly

Mistake: "60 mph equals about 100 km/h"

Problem: The correct value is 96.56 km/h, not 100 km/h (about 3.5% error).

Correct:

• 60 mph = 96.6 km/h (not 100 km/h)
• 100 mph = 160.9 km/h (not 160 km/h)
• 70 mph = 112.7 km/h (not 115 km/h)

Better approximation: Multiply mph by 1.6 for km/h:

• 60 × 1.6 = 96 km/h (very close)
• 70 × 1.6 = 112 km/h

2. Confusing Knots with mph

Mistake: Using knots and mph interchangeably

Problem: 1 knot = 1.15078 mph (about 15% difference)

Correct:

• 100 knots = 115 mph (not 100 mph)
• 200 knots = 230 mph (not 200 mph)
• 60 mph = 52 knots (not 60 knots)

When it matters: Aviation, maritime navigation, hurricane wind speeds (sometimes reported in both).

3. Forgetting Feet per Second Conversion

Mistake: "60 mph equals 60 feet per second"

Problem: 60 mph = 88 feet per second, not 60 ft/s.

Correct:

• 60 mph = 88 ft/s (multiply mph by 1.467)
• 30 mph = 44 ft/s
• 45 mph = 66 ft/s

Why it matters: Reaction time and stopping distance calculations for driving safety.

4. Ignoring Miles per Minute at 60 mph

Mistake: Not recognizing the clean relationship at 60 mph

Benefit: At exactly 60 mph, you travel 1 mile per minute:

• 60 mph for 30 minutes = 30 miles
• 60 mph for 90 minutes = 90 miles

Use it: Estimate arrival times easily when cruising at 60 mph.

5. UK vs US Speed Limit Confusion

Mistake: Assuming identical speed limits

Problem: UK and US have different speed limit philosophies.

US Interstate: 65-80 mph typical UK Motorway: 70 mph maximum

UK urban: 30 mph very common US urban: 25-35 mph varies more

6. Mixing Average Speed with Instantaneous Speed

Mistake: "My speedometer says 70 mph, so I'll get there in X time"

Problem: Average speed differs from speedometer reading due to stops, slow traffic, etc.

Reality:

• Highway: average 60-65 mph even with 70 mph speed limit
• City: average 20-30 mph even with 35-45 mph limits
• Account for stops, traffic, red lights

Unit Frequently Asked Questions

How do you convert mph to km/h?

Multiply mph by 1.60934 (or approximately 1.6 for quick mental math).

Formula: km/h = mph × 1.60934

Common conversions:

• 30 mph = 48.3 km/h (about 48 km/h)
• 60 mph = 96.6 km/h (about 97 km/h)
• 70 mph = 112.7 km/h (about 113 km/h)
• 100 mph = 160.9 km/h (about 161 km/h)

Quick mental trick: Multiply by 1.6 or use the "5 mph = 8 km/h" ratio.

Which countries use mph?

Primary mph users:

• United States: All 50 states, exclusively
• United Kingdom: Road signs only (railways use km/h)
• Some Caribbean nations: Antigua and Barbuda, Dominica, Grenada, Saint Lucia, Saint Vincent and the Grenadines

Total population: About 400 million people use mph daily (mostly US: 335M, UK: 67M).

Everyone else: 195+ other countries use km/h.

How fast is 60 mph?

60 mph means:

• 1 mile per minute (exactly)
• 88 feet per second
• 96.6 kilometers per hour
• 26.8 meters per second

Perspective:

• Typical highway cruising speed in US
• 60 mph stopping distance: ~271 feet (including reaction time)
• A car at 60 mph covers a football field length in 3.4 seconds

Reference speeds:

• Walking: 3-4 mph (15-20× slower than 60 mph)
• Urban driving: 30 mph (half of 60 mph)
• Highway limit: 65-75 mph (slightly faster than 60 mph)

What mph is a fast pitch in baseball?

MLB average fastball: ~93 mph (as of 2023 season)

Ranges:

• Major League: 90-100 mph typical for fastballs
• Record: 105.1 mph (Aroldis Chapman, 2010)
• College: 85-95 mph
• High school: 75-85 mph

Other pitches:

• Curveball: 70-80 mph (slower than fastball)
• Slider: 80-90 mph
• Changeup: 75-85 mph (designed to look like fastball but slower)

Is mph the same as knots?

No—knots are about 15% faster than mph:

1 knot = 1.15078 mph 1 mph = 0.868976 knots

Knot: 1 nautical mile per hour (nautical mile = 1.852 km = 1.15 statute miles)

When each is used:

• mph: Roads, US driving, US weather
• Knots: Aviation, maritime, international weather (hurricanes often reported in both)

Example:

• Hurricane with 100 knot winds = 115 mph winds
• Aircraft cruising at 500 knots = 575 mph

How many feet per second is 60 mph?

60 mph = 88 feet per second (exactly 88.0 ft/s)

Calculation: 60 miles/hour × 5,280 feet/mile ÷ 3,600 seconds/hour = 88 ft/s

General conversion: mph × 1.46667 = ft/s

Common speeds:

• 30 mph = 44 ft/s
• 45 mph = 66 ft/s
• 60 mph = 88 ft/s
• 70 mph = 102.7 ft/s

Why it matters: Reaction time and stopping distance. At 60 mph, you travel 88 feet every second—in the 1.5 seconds it takes to react, you've gone 132 feet.

What is a safe highway speed?

Speed limits vary, but 55-75 mph is typical for US highways.

Factors affecting safe speed:

• Posted speed limit
• Traffic flow (matching traffic speed is often safest)
• Weather conditions (reduce speed in rain, snow, fog)
• Road conditions (construction, curves, hills)
• Visibility

General guidelines:

• Dry conditions, light traffic: posted speed limit is safe
• Rain: reduce by 5-10 mph
• Heavy rain: reduce by 10-20 mph
• Snow/ice: reduce by 20-40 mph or more

Fuel economy consideration: 55-65 mph typically maximizes MPG; speeds above 70 mph significantly reduce fuel efficiency.

Why do cars have speedometers up to 140-160 mph?

Most cars won't reach their speedometer max, but there are several reasons for high readings:

Legal/Safety:

• Prevents speedometer needle from hitting the stop (bad for mechanism)
• Ensures accuracy across the full range
• Provides headroom for high-speed capability

Marketing:

• Higher numbers suggest performance capability
• Sports cars actually can reach those speeds (track use)

Practical maximum:

• Most economy cars: limited to 100-120 mph electronically
• Sports cars: 150-180 mph possible
• Supercars: 200+ mph capable

Note: Driving at extreme speeds is illegal on public roads in the US (highest limit: 85 mph in Texas).

How much faster is 70 mph than 60 mph?

16.7% faster (10 mph difference ÷ 60 mph = 16.7%)

Time difference over 120 miles:

• At 60 mph: 120 miles takes 2 hours
• At 70 mph: 120 miles takes 1 hour 43 minutes
• Time saved: 17 minutes (14% faster trip)

Fuel economy impact:

• 70 mph: approximately 10-15% worse MPG than 60 mph
• 80 mph: approximately 20-25% worse MPG than 60 mph

Trade-off: Going 70 mph instead of 60 mph saves about 14% time but costs 10-15% more fuel.

What wind speed is dangerous?

Depends on context, but general guidelines:

Driving hazards:

• 25-35 mph winds: difficult for high-profile vehicles (trucks, RVs)
• 40+ mph winds: dangerous for all vehicles, avoid driving if possible
• 60+ mph winds: extremely dangerous, structural damage likely

Personal safety (on foot):

• 40-50 mph: difficult to walk, risk of being blown over
• 60+ mph: cannot stand without shelter
• 75+ mph: hurricane-force winds, severe danger

Structural damage thresholds:

• 50-60 mph: tree branches break
• 70-80 mph: trees uprooted, roof damage
• 100+ mph: severe structural damage to buildings
• 150+ mph: catastrophic damage (EF4+ tornado, Cat 4-5 hurricane)

Quick Reference Card

Measurement	Value
1 mph equals	1.60934 km/h
	0.44704 m/s
	1.46667 ft/s
	0.868976 knots
Key reference	60 mph = 1 mile/minute
Common speeds	Walking: 3-4 mph
	Residential: 25-35 mph
	Highway: 65-75 mph
	Hurricane: 74+ mph
Baseball pitch	MLB fastball: 90-100 mph
Conversion trick	mph × 1.6 ≈ km/h

Your Next Steps

Ready to convert miles per hour to other speed units? Use our mph converter:

• Convert mph to km/h
• Convert mph to m/s
• Convert mph to ft/s
• Convert mph to knots

Explore related units:

• Kilometer per hour - Global speed standard
• Meter per second - SI speed unit
• Knot - Aviation and maritime speed
• Mile - The distance unit that defines mph