Millimeter (mm)
A small metric unit used for hardware, manufacturing tolerances, and thin materials.
Everyday converter
Length Converter
This length converter switches between feet, inches, meters, yards, miles, centimeters, and millimeters instantly in your browser. Every answer uses an exact factor, so only the figure on screen is rounded.
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Common length units
- Millimeter (mm)1 mm = 0.1 cm
- Centimeter (cm)1 cm = 10 mm
- Meter (m)1 m = 100 cm
- Kilometer (km)1 km = 1,000 m
- Inch (in)1 in = 2.54 cm exactly
- Foot (ft)1 ft = 12 in = 0.3048 m exactly
- Yard (yd)1 yd = 3 ft = 0.9144 m exactly
- Mile (mi)1 mi = 5,280 ft = 1.609344 km exactly
Conversion formula
Every conversion here uses an exact factor, not a rounded one.
Example: cm to inches
1 inch = 2.54 centimeters
So to convert centimeters to inches, divide by 2.54:
30 cm ÷ 2.54 = 11.811 in
The metric definitions of the inch, foot, yard, and mile have been exact since the 1959 international yard and pound agreement. Only the displayed answer is rounded.
Did you know?
One inch is exactly 2.54 centimeters — not approximately. The figure was fixed by agreement in 1959, which is why the same conversion gives the same answer wherever you do it.
It also means the mile is defined through the metre: 1 mile is exactly 1.609344 km, so a 5K is a shade over 3.1 miles.
Centimeters to inches
Convert centimeters to inches and inches to centimeters on one page. The international inch has an exact metric definition — 1 in = 2.54 cm — so both directions use the same single relationship, and neither is an approximation.
Formula: inches = centimeters ÷ 2.54, and the other way: centimeters = inches × 2.54
| Centimeters (cm) | Inches (in) |
|---|---|
| 1 cm | 0.3937 in |
| 2 cm | 0.7874 in |
| 5 cm | 1.9685 in |
| 10 cm | 3.937 in |
| 15 cm | 5.9055 in |
| 20 cm | 7.874 in |
| 25 cm | 9.8425 in |
| 30 cm | 11.811 in |
| 50 cm | 19.685 in |
| 75 cm | 29.5276 in |
Feet to meters
Convert feet to meters and meters to feet on one page. The foot is defined as exactly 0.3048 m, so both directions share one exact factor.
Formula: meters = feet × 0.3048, and the other way: feet = meters ÷ 0.3048
| Feet (ft) | Meters (m) |
|---|---|
| 1 ft | 0.3048 m |
| 2 ft | 0.6096 m |
| 3 ft | 0.9144 m |
| 5 ft | 1.524 m |
| 6 ft | 1.8288 m |
| 8 ft | 2.4384 m |
| 10 ft | 3.048 m |
| 12 ft | 3.6576 m |
| 20 ft | 6.096 m |
| 50 ft | 15.24 m |
Miles to kilometers
Convert miles to kilometers and kilometers to miles on one page. The international mile is exactly 1.609344 km, so neither direction is an estimate.
Formula: kilometers = miles × 1.609344, and the other way: miles = kilometers ÷ 1.609344
| Miles (mi) | Kilometers (km) |
|---|---|
| 1 mi | 1.6093 km |
| 2 mi | 3.2187 km |
| 3 mi | 4.828 km |
| 5 mi | 8.0467 km |
| 10 mi | 16.0934 km |
| 13.1 mi | 21.0824 km |
| 20 mi | 32.1869 km |
| 26.2 mi | 42.1648 km |
| 50 mi | 80.4672 km |
| 100 mi | 160.9344 km |
Millimeters to inches
Convert millimeters to inches for fasteners, tools, manufacturing drawings, electronics, and product dimensions. Since one inch is exactly 25.4 millimeters, small measurements can be converted consistently without using an approximate physical reference.
Formula: inches = millimeters ÷ 25.4
| Millimeters (mm) | Inches (in) |
|---|---|
| 1 mm | 0.0394 in |
| 2 mm | 0.0787 in |
| 3 mm | 0.1181 in |
| 5 mm | 0.1969 in |
| 6 mm | 0.2362 in |
| 8 mm | 0.315 in |
| 10 mm | 0.3937 in |
| 12 mm | 0.4724 in |
| 20 mm | 0.7874 in |
| 25 mm | 0.9843 in |
Yards to meters
Convert yards to meters for sports fields, fabric, landscaping, construction, and outdoor distances. The international yard is defined as exactly 0.9144 meters, which keeps the conversion consistent.
Formula: meters = yards × 0.9144
| Yards (yd) | Meters (m) |
|---|---|
| 1 yd | 0.9144 m |
| 2 yd | 1.8288 m |
| 5 yd | 4.572 m |
| 10 yd | 9.144 m |
| 20 yd | 18.288 m |
| 25 yd | 22.86 m |
| 50 yd | 45.72 m |
| 75 yd | 68.58 m |
| 100 yd | 91.44 m |
| 120 yd | 109.728 m |
Inches to feet
Convert total inches to decimal feet for furniture, lumber, room dimensions, signs, and height. This relationship stays within the US customary system: one foot contains exactly 12 inches.
Formula: feet = inches ÷ 12
| Inches (in) | Feet (ft) |
|---|---|
| 1 in | 0.0833 ft |
| 6 in | 0.5 ft |
| 12 in | 1 ft |
| 18 in | 1.5 ft |
| 24 in | 2 ft |
| 30 in | 2.5 ft |
| 36 in | 3 ft |
| 48 in | 4 ft |
| 60 in | 5 ft |
| 72 in | 6 ft |
How to use this converter
- Choose unitsSelect the source and destination units for the measurement.
- Enter a valueThe converted result updates from the maintained unit formula.
- Copy and verifyCopy the result and check the units and rounding required by the destination.
Processing and privacy
Conversion math runs locally in the browser without a calculation API. This category converter can store selected units and values in the page URL so a state can be restored or shared; avoid sharing a URL that contains a value you consider sensitive. Ordinary hosting and analytics are separate from the conversion logic.
Unit guide
Metric and imperial length units
Length measures the distance between two points. Metric units scale by powers of ten; US customary and imperial length units use fixed relationships such as 12 inches in a foot and 1,760 yards in a mile.
Centimeter (cm)
One hundredth of a meter, useful for product dimensions, body measurements, and schoolwork.
Meter and kilometer (m, km)
Meters suit rooms and buildings; kilometers suit roads, races, and travel distances.
Inch, foot, and yard (in, ft, yd)
Common US units for products, height, construction, fabric, and sports fields.
Mile (mi)
A long-distance unit used on roads in the United States and United Kingdom.
How the math works
Conversion formulas
- Inches to centimeterscentimeters = inches × 2.54Example: 12 inches × 2.54 = 30.48 centimeters
- Centimeters to inchesinches = centimeters ÷ 2.54Example: 100 centimeters ÷ 2.54 = 39.3701 inches
- Feet to metersmeters = feet × 0.3048Example: 6 feet × 0.3048 = 1.8288 meters
- Meters to feetfeet = meters ÷ 0.3048Example: 1 meter ÷ 0.3048 = 3.28084 feet
- Miles to kilometerskilometers = miles × 1.609344Example: 10 miles × 1.609344 = 16.09344 kilometers
- Kilometers to milesmiles = kilometers ÷ 1.609344Example: 5 kilometers ÷ 1.609344 = 3.10686 miles
- Yards to metersmeters = yards × 0.9144Example: 100 yards × 0.9144 = 91.44 meters
Quick reference
Length conversion chart
Quick length conversions Americans look up most. Factors are exact international definitions (1 inch = 2.54 cm, 1 foot = 0.3048 m, 1 mile = 1.609344 km).
Centimeters to inches
| Centimeters (cm) | Inches (in) |
|---|---|
| 1 cm | 0.3937 in |
| 2.54 cm | 1 in |
| 5 cm | 1.9685 in |
| 10 cm | 3.9370 in |
| 15 cm | 5.9055 in |
| 20 cm | 7.8740 in |
| 25 cm | 9.8425 in |
| 30 cm | 11.8110 in |
| 50 cm | 19.6850 in |
| 100 cm | 39.3701 in |
Inches to centimeters
| Inches (in) | Centimeters (cm) |
|---|---|
| 1 in | 2.54 cm |
| 2 in | 5.08 cm |
| 3 in | 7.62 cm |
| 4 in | 10.16 cm |
| 6 in | 15.24 cm |
| 12 in (1 ft) | 30.48 cm |
| 24 in (2 ft) | 60.96 cm |
| 36 in (1 yd) | 91.44 cm |
Feet to meters
| Feet (ft) | Meters (m) |
|---|---|
| 1 ft | 0.3048 m |
| 3 ft | 0.9144 m |
| 5 ft | 1.5240 m |
| 6 ft | 1.8288 m |
| 10 ft | 3.0480 m |
| 50 ft | 15.2400 m |
| 100 ft | 30.4800 m |
Meters to feet
| Meters (m) | Feet (ft) |
|---|---|
| 1 m | 3.2808 ft |
| 2 m | 6.5617 ft |
| 5 m | 16.4042 ft |
| 10 m | 32.8084 ft |
| 50 m | 164.0420 ft |
| 100 m | 328.0840 ft |
Miles to kilometers
| Miles (mi) | Kilometers (km) |
|---|---|
| 1 mi | 1.6093 km |
| 5 mi | 8.0467 km |
| 10 mi | 16.0934 km |
| 26.2 mi (marathon) | 42.1648 km |
| 50 mi | 80.4672 km |
| 100 mi | 160.9344 km |
Kilometers to miles
| Kilometers (km) | Miles (mi) |
|---|---|
| 1 km | 0.6214 mi |
| 5 km | 3.1069 mi |
| 10 km | 6.2137 mi |
| 21.0975 km (half marathon) | 13.1094 mi |
| 42.195 km (marathon) | 26.2188 mi |
| 100 km | 62.1371 mi |
Yards to meters
| Yards (yd) | Meters (m) |
|---|---|
| 1 yd | 0.9144 m |
| 10 yd | 9.1440 m |
| 50 yd | 45.7200 m |
| 100 yd | 91.4400 m |
| 120 yd | 109.7280 m |
Everyday use
Practical length conversion examples
Products and furniture
Convert metric package or furniture dimensions before checking whether an item fits a shelf, doorway, or room.
Travel and running
Compare kilometer road signs and race distances with miles, including 5K, 10K, and marathon distances.
Construction and DIY
Translate plans, fastener sizes, material lengths, and tool specifications while retaining enough precision for the job.
Context
Where these units are used
In the United States, everyday length is still mostly feet, inches, yards, and miles. Road signs, house plans, and sports fields use those units. Product packaging and tools from abroad often list centimeters or meters instead.
Metric length is the global default for science, medicine, and most export goods. A US reader often meets meters on a running race, a European listing, or a product label. This length converter keeps both systems side by side so you can match the unit on the page in front of you.
Frequently asked questions
How many inches is 5 cm?
5 cm is 1.9685 inches. Divide centimeters by 2.54 to convert to inches. 1 inch is exactly 2.54 cm.
How many miles is 10 km?
10 km is 6.2137 miles. Divide kilometers by 1.609344 to convert to miles. 1 mile is exactly 1.609344 km.
How many meters is 1 foot?
1 foot is exactly 0.3048 meters. Multiply feet by 0.3048 for meters. 3 feet is 0.9144 meters.
How many yards is 100 meters?
100 meters is 109.361 yards. One yard is exactly 0.9144 meters. Divide meters by 0.9144 to get yards.
Is this length converter free with no sign-up?
Yes. This converter is free with no sign-up and no account. Use it as often as you need in your browser.
How many inches is 10 cm?
10 cm is 3.9370 inches. Divide centimeters by 2.54 to get inches. 5 cm is 1.9685 inches and 30 cm is 11.811 inches.
How many cm is 12 inches?
12 inches is exactly 30.48 cm. Multiply inches by 2.54 to get centimeters. That is one foot, and 36 inches is 91.44 cm.
Does this page convert inches to cm too?
Yes, both directions run on this page. Enter centimeters to read inches, or enter inches to read centimeters. The chart lists both columns.
Is 1 inch exactly 2.54 cm?
Yes. The international inch is defined as exactly 2.54 centimeters. Neither direction of this conversion is an approximation.
How many meters is 10 feet?
10 feet is 3.048 meters. Multiply feet by 0.3048 to get meters. 20 feet is 6.096 meters.
How many feet is 3 meters?
3 meters is 9.84 feet. Divide meters by 0.3048 to get feet. 10 meters is 32.81 feet.
Does this page convert meters to feet as well?
Yes, both directions run here. Enter feet to read meters, or enter meters to read feet. The chart covers both.
Is a foot exactly 0.3048 meters?
Yes. The international foot is defined as exactly 0.3048 meters, so neither direction of this conversion is an estimate.
How many km is 5 miles?
5 miles is 8.05 kilometers. Multiply miles by 1.609344 to get kilometers. 10 miles is 16.09 km.
How far is a marathon in km?
A marathon is 26.2 miles, which is 42.16 kilometers. A half marathon is 13.1 miles, or 21.08 km.
Does this page convert km to miles as well?
Yes, both directions run here. Enter miles to read kilometers, or enter kilometers to read miles. The chart lists both.
How many inches is 1 mm?
1 mm is 0.03937 inches. Divide millimeters by 25.4. 1 inch is exactly 25.4 mm.
How many inches is 25.4 mm?
25.4 mm is exactly 1 inch. That is the international definition. 12.7 mm is exactly 0.5 inches.
How many inches is 50 mm?
50 mm is 1.9685 inches. Divide by 25.4 for inches. 100 mm is 3.9370 inches.
How many mm is 1 inch?
1 inch is exactly 25.4 mm. Multiply inches by 25.4 for millimeters. 2 inches is 50.8 mm.
How many meters is 1 yard?
1 yard is exactly 0.9144 meters. Multiply yards by 0.9144. 10 yards is 9.144 meters.
How many meters is 100 yards?
100 yards is exactly 91.44 meters. Multiply by 0.9144. 50 yards is 45.72 meters.
How many meters is 50 yards?
50 yards is exactly 45.72 meters. Multiply yards by 0.9144 for meters. 120 yards is 109.728 meters.
How many yards is 1 meter?
1 meter is 1.09361 yards. Divide meters by 0.9144 for yards. 10 meters is 10.9361 yards.
How many feet is 12 inches?
12 inches is exactly 1 foot. Divide inches by 12 for feet. 24 inches is exactly 2 feet.
How many feet is 36 inches?
36 inches is exactly 3 feet. Divide by 12. 60 inches is exactly 5 feet.
How many feet is 18 inches?
18 inches is 1.5 feet. Divide inches by 12. 30 inches is 2.5 feet.
How many inches is 1 foot?
1 foot is exactly 12 inches. Multiply feet by 12 for inches. 6 feet is 72 inches.