Length Converter
Convert between meters, feet, inches, miles, kilometers, and more length units.
About This Calculator
The Length Converter instantly converts between imperial and metric units including inches, feet, yards, miles, millimeters, centimeters, meters, and kilometers. Whether you're measuring for a home renovation project, converting your height for international travel documents, calculating fabric for sewing, or understanding road distances in a foreign country, this tool provides accurate real-time conversions across all common length units. The imperial system, used primarily in the United States, Liberia, and Myanmar, measures length in inches, feet, yards, and miles. The metric system, adopted by virtually every other country and all scientific disciplines, uses millimeters, centimeters, meters, and kilometers based on powers of 10. Converting between these systems is essential in our globalized worldโwhether you're ordering furniture from IKEA (metric dimensions), watching European sports (100-meter dash), or working with international specifications. Our converter handles every common scenario from converting feet to meters for ceiling heights, inches to centimeters for screen sizes, miles to kilometers for marathon training, or yards to meters for golf course distances. With over 95% of the world using metric, knowing how to convert between these measurement systems has become an essential everyday skill for travelers, online shoppers, students, and professionals alike.
How to Use the Length Converter
- 1Enter a value in any input field to begin conversion.
- 2Watch as all other unit fields update automatically in real-time.
- 3Click the copy button next to any result to copy it to your clipboard.
- 4Use Tab or click to move between fields for manual entry.
- 5Clear all fields by refreshing or entering 0 in any field.
- 6For decimal precision, enter values with decimal points (e.g., 5.75 feet).
- 7Common conversions: feet to meters for height, miles to km for distance.
- 8Bookmark this page for quick access during DIY projects or travel planning.
Complete Length Conversion Reference
Imperial System Conversions:
- 12 inches = 1 foot
- 3 feet = 1 yard
- 5,280 feet = 1 mile
- 1,760 yards = 1 mile
- 36 inches = 1 yard
Metric System Conversions:
- 10 millimeters = 1 centimeter
- 100 centimeters = 1 meter
- 1,000 meters = 1 kilometer
- 1,000 millimeters = 1 meter
Imperial to Metric Exact Conversions:
- 1 inch = 2.54 centimeters (exact by definition)
- 1 foot = 30.48 centimeters
- 1 yard = 0.9144 meters
- 1 mile = 1.609344 kilometers
Metric to Imperial Conversions:
- 1 centimeter = 0.3937 inches
- 1 meter = 3.28084 feet
- 1 meter = 1.09361 yards
- 1 kilometer = 0.621371 miles
Quick Mental Math Shortcuts
Inches to Centimeters: Multiply by 2.5 for quick estimate (actual: 2.54)
- 4 inches โ 10 cm
- 10 inches โ 25 cm
- 40 inches โ 100 cm (1 meter)
Feet to Meters: Divide by 3.3 or multiply by 0.3
- 3 feet โ 1 meter
- 6 feet โ 1.8 meters
- 10 feet โ 3 meters
Miles to Kilometers: Add 60% or multiply by 1.6
- 10 miles โ 16 km
- 60 miles โ 100 km
- 100 miles โ 160 km
Kilometers to Miles: Multiply by 0.6 (take 60%)
- 10 km โ 6 miles
- 100 km โ 60 miles
- 5 km โ 3 miles
Fibonacci Trick for km/miles: Each Fibonacci number in km โ previous number in miles:
- 5 km โ 3 miles, 8 km โ 5 miles, 13 km โ 8 miles
Height Conversion Chart: Feet/Inches to Centimeters
Common Height Conversions:
| Imperial | Metric | Notes |
|---|---|---|
| 4'10" | 147 cm | |
| 5'0" | 152 cm | |
| 5'2" | 157 cm | |
| 5'4" | 163 cm | Average US female |
| 5'6" | 168 cm | |
| 5'8" | 173 cm | |
| 5'9" | 175 cm | Average US male |
| 5'10" | 178 cm | |
| 6'0" | 183 cm | |
| 6'2" | 188 cm | |
| 6'4" | 193 cm | |
| 6'6" | 198 cm |
Height Conversion Formula: Total inches ร 2.54 = centimeters (Feet ร 12 + Inches) ร 2.54 = cm
Example: 5'8" = (5 ร 12 + 8) ร 2.54 = 68 ร 2.54 = 172.72 cm
Which Countries Use Which System
Imperial System (3 Countries):
- United States: Uses imperial for daily life, metric for science
- Liberia: Legacy from American founding
- Myanmar: Transitioning to metric
Metric System (190+ Countries):
- All of Europe, Asia, Africa, South America, Australia
- Canada: Officially metric since 1970s (some imperial persists)
- United Kingdom: Officially metric, but miles for roads, pints for beer
Mixed Usage in US:
- Science and medicine: Always metric
- Military: Metric since 1950s
- Auto industry: Largely metric
- Construction: Imperial (feet, inches)
- Real estate: Imperial (square feet)
- Food: Both (grams and ounces)
Industries Using Both Globally:
- Aviation: Feet for altitude, nautical miles for distance
- Shipping: TEU containers (20-foot equivalent units)
- Oil industry: Barrels (imperial) but pipelines in metric
- Screens: Inches worldwide (TVs, monitors, phones)
Running and Marathon Distances
Race Distance Conversions:
| Race | Metric | Imperial | Notes |
|---|---|---|---|
| Sprint | 100m | 328 ft | Olympic dash |
| Sprint | 200m | 656 ft | Half track |
| Sprint | 400m | 1,312 ft | One lap |
| Middle | 800m | 0.497 mi | Half mile |
| Mile | 1,609m | 1 mile | 4 laps |
| 5K | 5,000m | 3.11 mi | Popular race |
| 10K | 10,000m | 6.21 mi | Road race |
| Half Marathon | 21,097m | 13.11 mi | 13.1 miles |
| Marathon | 42,195m | 26.22 mi | 26.2 miles |
| Ultra | 50km | 31.07 mi | Trail race |
| 100 Mile | 160.9km | 100 mi | Ultramarathon |
Track Facts:
- Standard track: 400 meters per lap
- 4 laps = 1,600 meters โ 1 mile
- 25 laps = 10,000 meters (10K)
- Inside lane is 400m; outer lanes are longer
Construction and DIY Measurements
Standard Lumber Dimensions (Nominal vs Actual):
- 2ร4: Actually 1.5" ร 3.5" (38mm ร 89mm)
- 2ร6: Actually 1.5" ร 5.5" (38mm ร 140mm)
- 4ร4: Actually 3.5" ร 3.5" (89mm ร 89mm)
- 1ร12: Actually 0.75" ร 11.25" (19mm ร 286mm)
Standard Room Dimensions:
| Item | Imperial | Metric |
|---|---|---|
| Ceiling height | 8-9 ft | 2.4-2.7m |
| Door height | 6'8" | 203 cm |
| Door width | 32-36" | 81-91 cm |
| Stair tread | 10-11" | 25-28 cm |
| Stair riser | 7-7.5" | 18-19 cm |
US vs European Bed Sizes:
| US Size | Inches | Metric Equivalent |
|---|---|---|
| Twin | 38ร75 | 97ร191 cm |
| Full | 54ร75 | 137ร191 cm |
| Queen | 60ร80 | 152ร203 cm |
| King | 76ร80 | 193ร203 cm |
| Cal King | 72ร84 | 183ร213 cm |
Screen Size Measurements
How Screen Size is Measured: Screen size is the diagonal measurement from corner to corner. This standard applies worldwide, always in inches.
Common Screen Sizes:
| Device | Common Sizes | Diagonal in cm |
|---|---|---|
| Smartphone | 6.1", 6.7" | 15.5cm, 17cm |
| Tablet | 10.2", 12.9" | 26cm, 33cm |
| Laptop | 13", 15.6" | 33cm, 40cm |
| Monitor | 24", 27", 32" | 61cm, 69cm, 81cm |
| TV | 55", 65", 75" | 140cm, 165cm, 190cm |
Optimal Viewing Distance:
- TVs: Screen size ร 1.5-2.5 = viewing distance
- 55" TV: Sit 6.9-11.5 feet (2.1-3.5m) away
- 65" TV: Sit 8.1-13.5 feet (2.5-4.1m) away
- Monitors: Arm's length (20-40 inches / 50-100 cm)
Why Inches for Screens Worldwide: Television technology originated in the US and UK. By the time other countries developed markets, inches were the established standard. Global manufacturers kept inches for consistency.
The History of Length Measurement
Ancient Measurement Systems:
- Cubit (Egypt): Forearm length, ~18 inches (45 cm)
- Foot (Roman): Based on human foot, ~11.6 inches (29.6 cm)
- Pace (Rome): Double step, about 5 feet (1.5m)
Origin of Modern Units:
- Inch: Originally three barleycorns laid end to end (King Edward II, 1324)
- Foot: King Henry I decreed it as the length of his foot (12 inches)
- Yard: Henry I's arm, nose to fingertip (3 feet)
- Mile: Roman "mille passus" (1,000 paces = 5,000 Roman feet)
Creation of the Metric System:
- 1791: France adopts meter based on Earth's meridian
- 1799: Platinum meter bar created as official standard
- 1875: Treaty of the Metre signed by 17 nations
- 1960: SI system adopted with meter redefined by wavelength of light
- 2019: Meter redefined using speed of light (299,792,458 m/s exactly)
The Meter Definition Today: The meter is defined as the distance light travels in a vacuum in 1/299,792,458 of a second. This makes it the most precisely defined length unit in human history.
Travel and International Conversions
Road Speed Conversions:
| MPH | KM/H | Common Usage |
|---|---|---|
| 25 | 40 | School zone |
| 35 | 56 | City streets |
| 55 | 89 | US highways |
| 65 | 105 | US interstate |
| 70 | 113 | US interstate |
| 75 | 121 | Texas highways |
| 100 | 161 | Autobahn common |
| 130 | 209 | Autobahn advisory |
Flight Altitude Conversions:
- 10,000 ft = 3,048 m (cabin pressure change point)
- 30,000 ft = 9,144 m (typical cruise)
- 40,000 ft = 12,192 m (high cruise altitude)
Mountain Elevations:
| Peak | Feet | Meters |
|---|---|---|
| Mt. Everest | 29,032 | 8,849 |
| K2 | 28,251 | 8,611 |
| Mt. Kilimanjaro | 19,341 | 5,895 |
| Mt. Blanc | 15,781 | 4,810 |
| Mt. Rainier | 14,411 | 4,392 |
| Pikes Peak | 14,115 | 4,302 |
Ocean Depths:
- Titanic wreck: 12,500 ft (3,810 m)
- Mariana Trench: 36,000 ft (10,972 m)
Sports Field Dimensions
Football/Soccer Fields:
| Field Type | Length | Width |
|---|---|---|
| NFL Football | 360 ft (120 yd) | 160 ft (53.3 yd) |
| Soccer (FIFA) | 330-360 ft | 210-240 ft |
| Soccer (FIFA) | 100-110 m | 64-75 m |
| Canadian Football | 450 ft (150 yd) | 195 ft (65 yd) |
Basketball Courts:
| Court | Length | Width |
|---|---|---|
| NBA | 94 ft (28.7 m) | 50 ft (15.2 m) |
| NCAA | 94 ft (28.7 m) | 50 ft (15.2 m) |
| FIBA | 91.9 ft (28 m) | 49.2 ft (15 m) |
| High School | 84 ft (25.6 m) | 50 ft (15.2 m) |
Golf Courses:
- Par 3: 100-250 yards (91-229 m)
- Par 4: 251-470 yards (230-430 m)
- Par 5: 471-690 yards (431-631 m)
- Full course: 5,000-7,500 yards (4.6-6.9 km)
Swimming Pools:
- Olympic: 50 meters (164 ft)
- Short course: 25 meters (82 ft)
- US short course: 25 yards (22.9 m)
Paper and Printing Sizes
US Paper Sizes:
| Name | Inches | Millimeters |
|---|---|---|
| Letter | 8.5 ร 11 | 216 ร 279 |
| Legal | 8.5 ร 14 | 216 ร 356 |
| Tabloid | 11 ร 17 | 279 ร 432 |
| Ledger | 17 ร 11 | 432 ร 279 |
ISO A-Series (International):
| Name | Millimeters | Inches |
|---|---|---|
| A0 | 841 ร 1189 | 33.1 ร 46.8 |
| A1 | 594 ร 841 | 23.4 ร 33.1 |
| A2 | 420 ร 594 | 16.5 ร 23.4 |
| A3 | 297 ร 420 | 11.7 ร 16.5 |
| A4 | 210 ร 297 | 8.3 ร 11.7 |
| A5 | 148 ร 210 | 5.8 ร 8.3 |
| A6 | 105 ร 148 | 4.1 ร 5.8 |
Photography Prints:
| Size | Inches | Centimeters |
|---|---|---|
| Wallet | 2.5 ร 3.5 | 6.4 ร 8.9 |
| 4R | 4 ร 6 | 10 ร 15 |
| 5R | 5 ร 7 | 13 ร 18 |
| 8R | 8 ร 10 | 20 ร 25 |
| 11R | 11 ร 14 | 28 ร 36 |
Pro Tips
- ๐กMemorize 2.54โthe exact conversion factor from inches to centimeters.
- ๐กFor km to miles, multiply by 0.6. For miles to km, multiply by 1.6.
- ๐กA meter is roughly a yard plus 3 inches (1.09 yards exactly).
- ๐กUse the "30 cm = 1 foot" rule for quick estimates (actual: 30.48 cm).
- ๐กFor height conversion: total inches ร 2.54 = centimeters.
- ๐ก5K race = 3.1 miles, 10K = 6.2 miles, marathon = 26.2 miles.
- ๐กEU clothing sizes use centimeters; measure in inches and multiply by 2.54.
- ๐กLumber "2ร4" is actually 1.5" ร 3.5"โalways verify actual dimensions.
- ๐กScreen sizes are diagonal measurements, always in inches globally.
- ๐กOptimal TV viewing distance: screen size ร 1.5 to 2.5 times.
- ๐กThe Fibonacci sequence approximates km/mile conversions: 8 km โ 5 miles.
- ๐กWhen traveling in metric countries, remember: 100 km/h โ 60 mph.
Frequently Asked Questions
There are exactly 2.54 centimeters in one inch. This is a defined constant established in 1959 when English-speaking nations agreed to the international inch. To convert inches to cm, multiply by 2.54. To convert cm to inches, divide by 2.54 (or multiply by 0.3937).
