Unit & Measurement Tables
Length Conversion Table
Length is the one measurement almost everybody converts weekly and almost nobody converts consistently. A person who is 1.83 m tall is also 6 ft 0 in, and 72 inches, and 2 yards — four descriptions of the same body, and each one is the right answer to a different question. The table below exists so you can look up the number you need without re-deriving it from scratch.
Every figure here traces back to a single legal fact: since the 1959 international yard and pound agreement, one inch is defined as exactly 25.4 millimetres. Feet, yards and miles are multiples of that inch, so the entire imperial system of length rests on one number with no rounding anywhere in the chain. That is why a conversion from metres to feet can be trusted to four decimal places — it is a division, not an estimate.
The first table runs from half a metre to ten kilometres, which covers furniture, rooms, running distances and travel. The second runs the other way, from one foot to a hundred feet, for people who have a measurement in feet and need it in metres. The third lists the factors themselves, so you can extend the table to a value it does not contain.
Metres to feet, inches, yards and miles
| Metres | Feet | Inches | Yards | Miles |
|---|---|---|---|---|
| 0.5 | 1.64 | 19.7 | 0.547 | 0.0003 |
| 1 | 3.281 | 39.4 | 1.094 | 0.0006 |
| 1.5 | 4.921 | 59.1 | 1.64 | 0.0009 |
| 2 | 6.562 | 78.7 | 2.187 | 0.0012 |
| 3 | 9.843 | 118.1 | 3.281 | 0.0019 |
| 5 | 16.404 | 196.9 | 5.468 | 0.0031 |
| 10 | 32.808 | 393.7 | 10.936 | 0.0062 |
| 20 | 65.617 | 787.4 | 21.872 | 0.0124 |
| 50 | 164.042 | 1,968.5 | 54.681 | 0.0311 |
| 100 | 328.084 | 3,937 | 109.361 | 0.0621 |
| 500 | 1,640.42 | 19,685 | 546.807 | 0.3107 |
| 1,000 | 3,280.84 | 39,370.1 | 1,093.613 | 0.6214 |
| 5,000 | 16,404.199 | 196,850.4 | 5,468.066 | 3.1069 |
| 10,000 | 32,808.399 | 393,700.8 | 10,936.133 | 6.2137 |
Rounded to 1–4 decimals. The metres column is the exact input; every other column is derived from it.
Feet and inches to metres and centimetres
| Feet | Inches | Metres | Centimetres |
|---|---|---|---|
| 1 | 12 | 0.305 | 30.5 |
| 2 | 24 | 0.61 | 61 |
| 3 | 36 | 0.914 | 91.4 |
| 4 | 48 | 1.219 | 121.9 |
| 5 | 60 | 1.524 | 152.4 |
| 6 | 72 | 1.829 | 182.9 |
| 8 | 96 | 2.438 | 243.8 |
| 10 | 120 | 3.048 | 304.8 |
| 20 | 240 | 6.096 | 609.6 |
| 50 | 600 | 15.24 | 1,524 |
| 100 | 1,200 | 30.48 | 3,048 |
1 ft = 12 in = 0.3048 m exactly, so feet to centimetres is a single multiplication by 30.48.
Exact conversion factors, in metres
| Unit | Metres | Feet | Inches |
|---|---|---|---|
| 1 millimetre | 0.001 | 0.00328084 | 0.0393701 |
| 1 centimetre | 0.01 | 0.0328084 | 0.393701 |
| 1 inch | 0.0254 | 0.083333 | 1 |
| 1 foot | 0.3048 | 1 | 12 |
| 1 yard | 0.9144 | 3 | 36 |
| 1 metre | 1 | 3.28084 | 39.3701 |
| 1 kilometre | 1000 | 3,280.84 | 39,370.1 |
| 1 mile | 1,609.344 | 5,280 | 63,360 |
| 1 nautical mile | 1,852 | 6,076.1 | 72,913.4 |
The first six rows are exact by definition; the nautical mile is exact at 1852 m but does not divide evenly into feet.
How to Use These Tables
- Read across a row, never down a column. Each row is one physical length described in several units, so the numbers on the same row are equal to each other.
- For a value that is not in the table, multiply by the factor in the third table. Metres to feet is m × 3.280 84; feet to metres is ft × 0.3048.
- Do not round intermediate steps when you chain conversions. Going miles to kilometres to metres and back loses precision if you round at each hop.
- Inches to centimetres is the one conversion worth memorising exactly: multiply by 2.54. Everything else in the imperial system can be rebuilt from it.
Common Questions
How many feet are in a metre?
One metre is 3.280 839 895 feet. The commonly quoted 3.28 is short by about 0.001 ft per metre, which becomes a visible error past roughly 30 m — a 100 m sprint would come out about 3 cm short.
Is a mile exactly 1.609 kilometres?
No — a mile is 1.609 344 km exactly, which is why the rounded 1.6 is only safe for mental arithmetic. Over a marathon the gap between 1.6 and 1.609 344 works out to about 250 m, which is roughly a minute of running.
Why do nautical miles not appear in the main table?
A nautical mile is 1852 m by definition, which is not a whole multiple of a foot, so it does not fit the imperial columns cleanly. It is listed separately in the factors table and is used for aviation and marine distances only.
How do I convert feet and inches together, like 5 ft 9 in?
Turn the inches into feet first: 9 in is 0.75 ft, so the total is 5.75 ft. Multiply by 0.3048 to get 1.7526 m. Doing it the other way — converting 5 ft, then 9 in, then adding — gives the same answer but invites rounding twice.
Is a yard the same as a metre?
Close but not equal: a yard is 0.9144 m, so a metre is about 9.4 cm longer. Over 100 yards the gap is 8.6 m, which is why a 100-yard swim and a 100-metre swim are different events with different records.
More Unit & Measurement Tables
Sources
- NIST Special Publication 811 — Guide for the Use of the International System of Units — National Institute of Standards and Technology
- The International System of Units (SI Brochure), 9th edition — Bureau International des Poids et Mesures
- NIST Handbook 44 — Specifications, Tolerances and Other Technical Requirements — National Institute of Standards and Technology
Filed with Unit Conversion calculations.