Inches, feet, metres and miles: the length conversions people actually make
Nearly every country in the world measures distance in metres and kilometres. The United States, and to some degree the UK, still uses inches, feet and miles. So the conversions below are the ones that show up in daily life — on furniture listings, gym apps, running routes, school forms and hardware stores — not just in a textbook. Type any value into the tool above and the answer updates as you type, in either direction.
A worked example you can copy
Say a shop lists a desk as 5 feet 6 inches wide, but you measure your room in centimetres. Convert the feet-and-inches to inches first: (5 × 12) + 6 = 66 inches. Then multiply by the exact factor — 66 × 2.54 = 167.6 cm. That is the same number the tool returns, because 1 inch is defined as exactly 2.54 cm by international agreement; nothing is rounded. The reverse is equally common: a 10 km run is 10 × 0.621371 = 6.21 miles.
Height conversion chart (feet & inches to centimetres)
Converting a person's height between feet-and-inches and centimetres is one of the most-searched length questions — for visa forms, fitness profiles, or comparing heights with friends abroad. Here are the everyday values:
| Feet & inches | Total inches | Centimetres |
|---|---|---|
| 5'0" | 60" | 152.4 cm |
| 5'2" | 62" | 157.5 cm |
| 5'4" | 64" | 162.6 cm |
| 5'6" | 66" | 167.6 cm |
| 5'8" | 68" | 172.7 cm |
| 5'10" | 70" | 177.8 cm |
| 6'0" | 72" | 182.9 cm |
| 6'2" | 74" | 188.0 cm |
The maths: 1 inch is exactly 2.54 cm, so multiply total inches by 2.54. For example, 5'9" is 69 inches × 2.54 = 175.3 cm. Going the other way, divide centimetres by 2.54 to get total inches, then divide by 12 to separate feet from inches.
Paper sizes and screens: conversions hiding in plain sight
Two everyday things use odd units: paper and screens. An A4 sheet is 210 × 297 mm (8.27 × 11.69 in), while the US "Letter" size is 8.5 × 11 in (215.9 × 279.4 mm) — close enough that both print nearly interchangeably, but not identical. Screens are sized by their diagonal in inches: a 27-inch monitor has a 68.58 cm diagonal, and the phone in your pocket is likely 6.1–6.7 inches (15.5–17 cm). If you buy a desk or monitor from another country, checking these dimensions against your space in centimetres saves a return trip.
Every unit on this tool, and when you'd use it
- Everyday metric: millimetres and centimetres for small objects and fabric, metres for rooms and heights, kilometres for roads and runs.
- Everyday imperial: inches for screens and hardware, feet for height and room dimensions, yards for fabric and sports fields, miles for distance.
- Micron and atomic scale: micrometres, nanometres and angstroms for engineering tolerances, chip manufacturing and wavelengths of light.
- Survey and navigation: the nautical mile (exactly 1,852 m) for aviation and shipping, the fathom (1.8288 m) for water depth, and the furlong for horse racing.
- Astronomical: the astronomical unit (Earth–Sun distance, ~149.6 million km), the light-year (~9.46 trillion km), and the parsec (~3.26 light-years) for space.
Common conversion factors worth remembering
| From Unit | To Unit | Exact Factor |
|---|---|---|
| Inches (in) | Centimetres (cm) | 2.54 |
| Feet (ft) | Metres (m) | 0.3048 |
| Yards (yd) | Metres (m) | 0.9144 |
| Miles (mi) | Kilometres (km) | 1.609344 |
| Metres (m) | Feet (ft) | 3.280840 |
| Kilometres (km) | Miles (mi) | 0.621371 |
Length questions that come up again and again
How tall is 170 cm in feet and inches?
Divide 170 by 2.54 to get 66.93 inches, then split by 12: that's 5 feet with 6.93 inches left over — so 170 cm is about 5'7". The chart above covers the full range.
Is an American mile the same as a mile elsewhere?
Yes, the statute mile is 5,280 feet (1,609.344 m) everywhere. The thing people confuse is the nautical mile, which is 1,852 m and is used in aviation and shipping because it corresponds to one minute of latitude.
What is a light-year exactly?
A light-year is a distance, not a time: the distance light travels in one Earth year, about 9.46 trillion kilometres. The nearest star, Proxima Centauri, is about 4.24 light-years away. The parsec is related — 1 parsec ≈ 3.26 light-years.
Why does the US still use feet and miles?
The US customary system descends from the British imperial units. There have been several attempts to metricate since the 1970s, but the cost of changing roads, machinery, packaging and habits has kept it entrenched — so the two systems will keep meeting on this page.