Common length conversions
| From | To | Multiply by |
|---|---|---|
| Kilometres | Miles | 0.621371 |
| Miles | Kilometres | 1.609344 |
| Metres | Feet | 3.28084 |
| Feet | Metres | 0.3048 |
| Centimetres | Inches | 0.393701 |
| Inches | Centimetres | 2.54 |
Metric and imperial units
The metric system goes up in steps of ten: 10 millimetres make a centimetre, 100 centimetres make a metre and 1,000 metres make a kilometre. Imperial units do not: there are 12 inches in a foot, 3 feet in a yard and 1,760 yards in a mile. That is why converting by hand is easy to get wrong, and why the table under the result shows your value in every unit at once.
Since 1959 the inch has been defined as exactly 2.54 cm, so every conversion between the two systems is exact, not an estimate.
Worked example: your height
Doctors’ forms and visa applications often ask for your height in centimetres. If you are 5 ft 7 in tall, first turn it into inches: 5 × 12 + 7 = 67 inches. Then multiply by 2.54: 67 × 2.54 = 170.18 cm. To go the other way, divide centimetres by 2.54 to get inches, then divide by 12 for feet.
Tips
- A nautical mile (1,852 m) is used at sea and in the air. It is longer than a normal mile.
- Road signs in Pakistan and India use kilometres; the UK and the US use miles.
- For plot and room sizes, use the area converter instead: square feet are not the same as feet.