How to use this length converter
- Enter the measurement, choose its current unit under From unit, and choose the unit you need under To unit. Select Convert or press Enter to confirm the value. The answer stays blank while you are editing so an older result cannot be mistaken for the new one. After a successful conversion, changing either unit recalculates immediately. Swap units reverses the pair and moves the full-precision result into the input, which is useful for checking the opposite direction.
- The page supports millimetres, centimetres, metres, kilometres, inches, feet, yards, and international miles in one converter. Copy result includes the original number, both unit symbols, the converted number, and any practical fractional display. The tool is intended for measurements you already know: room dimensions, heights, craft pieces, maps, product specifications, or travel distances. It does not calculate area, volume, scale drawings, or routes.
Decimals, fractional inches, and feet plus inches
Most values can be typed as ordinary decimals, such as 2.5 or 0.025. When Inches is the source unit, you can also enter a mixed fraction such as 7 1/2 or a fraction smaller than one inch such as 3/8. When Feet is the source unit, use notation such as 5' 7 1/2" or 5 ft 7 1/2 in. The inches part must be below 12, and a fraction must be proper: enter 1 1/4 rather than 5/4.
When the target is inches, the converter adds an approximate mixed-inch value rounded to the nearest 1/16 inch. When the target is feet, it adds feet plus inches at the same resolution. The decimal result remains the main mathematical answer; the fraction is a practical measuring-tape approximation. Rounding can carry 11 15/16 inches into the next foot, so a value close enough to 6 feet is displayed as 6 ft 0 in rather than 5 ft 12 in.
How the conversion works
Each supported unit is related to metres, then expressed in the selected target unit. Metric units follow powers of ten: 1 metre equals 1,000 millimetres or 100 centimetres, and 1 kilometre equals 1,000 metres. The international inch is exactly 0.0254 metre. From that definition, 1 foot is 12 inches or 0.3048 metre, 1 yard is 3 feet or 0.9144 metre, and 1 international mile is 1,760 yards or 1,609.344 metres.
The converter keeps the unrounded numeric value through the calculation and rounds only the displayed result. Ordinary values show at most two decimal places and omit unnecessary trailing zeros. A small positive result keeps additional significant digits instead of becoming a misleading zero, while extremely small or large values use scientific notation. A physical measurement may still be less precise than the exact unit definition, so report only the precision justified by the original measurement.
Worked examples and common uses
Example 1 — convert 2.5 metres to feet. Since one foot is 0.3048 metre, 2.5 ÷ 0.3048 gives 8.202099… feet, displayed as 8.2 ft. The practical result is approximately 8 ft 2 7/16 in to the nearest sixteenth. This is useful for comparing a metric room or furniture dimension with an imperial tape measure.
Example 2 — convert 5' 7 1/2" to centimetres. Choose Feet, enter the combined notation, and convert to Centimetres. Five feet plus 7.5 inches is 67.5 inches; multiplying by exactly 2.54 gives 171.45 cm. The parser treats the feet-and-inches expression as one length, so no separate calculation or page is required.
Example 3 — convert 10 kilometres to miles. Dividing 10,000 metres by 1,609.344 gives 6.213711… miles, displayed as 6.21 mi. This is useful for a race distance, a road sign, or comparing travel information between unit systems. The result is a unit conversion only; it does not estimate travel time or choose a route.
Input rules, limits, and using the result
Zero is valid; negative length is rejected. Use a point as the decimal separator in every language and omit grouping commas and unit text, except for the documented feet-and-inches forms. Scientific notation such as 1e-6 is accepted for decimal inputs. Blank values, malformed fractions, a zero denominator, 12 or more inches inside a feet expression, and values beyond the browser numeric range produce a specific message without deleting the entry.
This page uses the international inch, foot, yard, and mile. It does not provide the older U.S. survey foot or nautical mile, and it does not convert pixels, typographic points, light-years, chains, or regional historical units. It also does not infer a real-world object’s length from a photo. For surveying, engineering tolerances, manufacturing, safety-critical work, or a contractual specification, confirm the required unit definition and allowed rounding with the governing document.
Use Copy result when moving an answer into notes, a quote, a worksheet, or a message; the copied text retains unit labels and the fraction approximation where applicable. No history or cloud record is created, so save the copied statement before closing the tab if you need it later. If another calculation will depend on the answer, use the decimal result or Swap units rather than manually re-entering the rounded fraction.
Frequently asked questions
How many centimetres are in one inch?
One international inch is exactly 2.54 centimetres. This exact definition is used for every imperial-to-metric conversion on this page.
Can I type feet and inches together?
Yes. Select Feet and enter a form such as 5' 7 1/2" or 5 ft 7 1/2 in. Keep the inches part below 12.
Why is the fraction different from the decimal result?
The decimal is the calculated result. The fraction is an additional approximation rounded to the nearest 1/16 inch so it is practical on a typical tape measure.
Are negative lengths accepted?
No. Zero is accepted, but a negative length is outside this converter’s measurement scope and produces an error.
Does changing a unit recalculate automatically?
Before the first Convert, unit changes keep the result blank. After a successful Convert, unit changes recalculate immediately until you edit the numeric input again.
All length conversion tables · 56 combinations
Use any of these conversions in the same calculator. Each direction is listed with unit symbols and full unit names, so you can search or start with the wording you already have.
conversions from Millimetres (mm) · 7 combinations
| Conversion direction | Formula | Example |
|---|---|---|
| Millimetres to Centimetres (mm to cm) | cm = mm × 0.1 | 1 mm = 0.1 cm |
| Millimetres to Metres (mm to m) | m = mm × 0.001 | 10 mm = 0.01 m |
| Millimetres to Kilometres (mm to km) | km = mm × 0.000001 | 10000 mm = 0.01 km |
| Millimetres to Inches (mm to in) | in ≈ mm × 0.03937007874 | 1 mm ≈ 0.03937007874 in |
| Millimetres to Feet (mm to ft) | ft ≈ mm × 0.003280839895 | 10 mm ≈ 0.03280839895 ft |
| Millimetres to Yards (mm to yd) | yd ≈ mm × 0.001093613298 | 10 mm ≈ 0.01093613298 yd |
| Millimetres to Miles (mm to mi) | mi ≈ mm × 6.21371192e-7 | 1000000 mm ≈ 0.6213711922 mi |
conversions from Centimetres (cm) · 7 combinations
| Conversion direction | Formula | Example |
|---|---|---|
| Centimetres to Millimetres (cm to mm) | mm = cm × 10 | 1 cm = 10 mm |
| Centimetres to Metres (cm to m) | m = cm × 0.01 | 1 cm = 0.01 m |
| Centimetres to Kilometres (cm to km) | km = cm × 0.00001 | 1000 cm = 0.01 km |
| Centimetres to Inches (cm to in) | in ≈ cm × 0.3937007874 | 1 cm ≈ 0.3937007874 in |
| Centimetres to Feet (cm to ft) | ft ≈ cm × 0.03280839895 | 1 cm ≈ 0.03280839895 ft |
| Centimetres to Yards (cm to yd) | yd ≈ cm × 0.01093613298 | 1 cm ≈ 0.01093613298 yd |
| Centimetres to Miles (cm to mi) | mi ≈ cm × 0.000006213711922 | 10000 cm ≈ 0.06213711922 mi |
conversions from Metres (m) · 7 combinations
| Conversion direction | Formula | Example |
|---|---|---|
| Metres to Millimetres (m to mm) | mm = m × 1000 | 1 m = 1000 mm |
| Metres to Centimetres (m to cm) | cm = m × 100 | 1 m = 100 cm |
| Metres to Kilometres (m to km) | km = m × 0.001 | 10 m = 0.01 km |
| Metres to Inches (m to in) | in ≈ m × 39.37007874 | 1 m ≈ 39.37007874 in |
| Metres to Feet (m to ft) | ft ≈ m × 3.280839895 | 1 m ≈ 3.280839895 ft |
| Metres to Yards (m to yd) | yd ≈ m × 1.093613298 | 1 m ≈ 1.093613298 yd |
| Metres to Miles (m to mi) | mi ≈ m × 0.0006213711922 | 100 m ≈ 0.06213711922 mi |
conversions from Kilometres (km) · 7 combinations
| Conversion direction | Formula | Example |
|---|---|---|
| Kilometres to Millimetres (km to mm) | mm = km × 1000000 | 1 km = 1000000 mm |
| Kilometres to Centimetres (km to cm) | cm = km × 100000 | 1 km = 100000 cm |
| Kilometres to Metres (km to m) | m = km × 1000 | 1 km = 1000 m |
| Kilometres to Inches (km to in) | in ≈ km × 39370.07874 | 1 km ≈ 39370.07874 in |
| Kilometres to Feet (km to ft) | ft ≈ km × 3280.839895 | 1 km ≈ 3280.839895 ft |
| Kilometres to Yards (km to yd) | yd ≈ km × 1093.613298 | 1 km ≈ 1093.613298 yd |
| Kilometres to Miles (km to mi) | mi ≈ km × 0.6213711922 | 1 km ≈ 0.6213711922 mi |
conversions from Inches (in) · 7 combinations
| Conversion direction | Formula | Example |
|---|---|---|
| Inches to Millimetres (in to mm) | mm = in × 25.4 | 1 in = 25.4 mm |
| Inches to Centimetres (in to cm) | cm = in × 2.54 | 1 in = 2.54 cm |
| Inches to Metres (in to m) | m = in × 0.0254 | 1 in = 0.0254 m |
| Inches to Kilometres (in to km) | km ≈ in × 0.0000254 | 1000 in = 0.0254 km |
| Inches to Feet (in to ft) | ft ≈ in × 0.08333333333 | 1 in ≈ 0.08333333333 ft |
| Inches to Yards (in to yd) | yd ≈ in × 0.02777777778 | 1 in ≈ 0.02777777778 yd |
| Inches to Miles (in to mi) | mi ≈ in × 0.00001578282828 | 1000 in ≈ 0.01578282828 mi |
conversions from Feet (ft) · 7 combinations
| Conversion direction | Formula | Example |
|---|---|---|
| Feet to Millimetres (ft to mm) | mm = ft × 304.8 | 1 ft = 304.8 mm |
| Feet to Centimetres (ft to cm) | cm = ft × 30.48 | 1 ft = 30.48 cm |
| Feet to Metres (ft to m) | m = ft × 0.3048 | 1 ft = 0.3048 m |
| Feet to Kilometres (ft to km) | km ≈ ft × 0.0003048 | 100 ft ≈ 0.03048 km |
| Feet to Inches (ft to in) | in ≈ ft × 12 | 1 ft ≈ 12 in |
| Feet to Yards (ft to yd) | yd ≈ ft × 0.3333333333 | 1 ft ≈ 0.3333333333 yd |
| Feet to Miles (ft to mi) | mi ≈ ft × 0.0001893939394 | 100 ft ≈ 0.01893939394 mi |
conversions from Yards (yd) · 7 combinations
| Conversion direction | Formula | Example |
|---|---|---|
| Yards to Millimetres (yd to mm) | mm = yd × 914.4 | 1 yd = 914.4 mm |
| Yards to Centimetres (yd to cm) | cm = yd × 91.44 | 1 yd = 91.44 cm |
| Yards to Metres (yd to m) | m = yd × 0.9144 | 1 yd = 0.9144 m |
| Yards to Kilometres (yd to km) | km = yd × 0.0009144 | 100 yd = 0.09144 km |
| Yards to Inches (yd to in) | in = yd × 36 | 1 yd = 36 in |
| Yards to Feet (yd to ft) | ft = yd × 3 | 1 yd = 3 ft |
| Yards to Miles (yd to mi) | mi ≈ yd × 0.0005681818182 | 100 yd ≈ 0.05681818182 mi |
conversions from Miles (mi) · 7 combinations
| Conversion direction | Formula | Example |
|---|---|---|
| Miles to Millimetres (mi to mm) | mm = mi × 1609344 | 1 mi = 1609344 mm |
| Miles to Centimetres (mi to cm) | cm = mi × 160934.4 | 1 mi = 160934.4 cm |
| Miles to Metres (mi to m) | m = mi × 1609.344 | 1 mi = 1609.344 m |
| Miles to Kilometres (mi to km) | km = mi × 1.609344 | 1 mi = 1.609344 km |
| Miles to Inches (mi to in) | in ≈ mi × 63360 | 1 mi ≈ 63360 in |
| Miles to Feet (mi to ft) | ft = mi × 5280 | 1 mi = 5280 ft |
| Miles to Yards (mi to yd) | yd = mi × 1760 | 1 mi = 1760 yd |