Conversion factors
1 in = 2.54 cm 1 ft = 12 in = 0.3048 m 1 yd = 3 ft = 0.9144 m 1 mi = 5,280 ft = 1,609.344 m 1 nmi = 1,852 m
All of these are exact by definition. The inch, foot, yard and mile have been defined in terms of the meter by the 1959 international yard and pound agreement; the nautical mile is defined as exactly 1,852 meters.
How the conversion works
The value is converted to meters, then from meters to the target unit. Results are rounded to about six significant figures for display; whole numbers are shown in full.
To convert by hand, multiply by how many target units fit in one of the units you have: one foot is 0.3048 m, so 6 ft × 0.3048 = 1.8288 m. If you only know the factor the other way round, divide by it instead: 30 cm ÷ 2.54 = 11.811 in.
Converting height to feet and inches
- Divide the height in centimeters by 2.54 to get inches: 175 ÷ 2.54 = 68.898 in.
- Divide by 12 to get whole feet: 68.898 ÷ 12 = 5, with 60 inches used.
- The rest is inches: 68.898 − 60 = 8.9 in.
- So 175 cm is about 5 ft 8.9 in, which most people would round to 5′9″.
Going the other way, turn the height into inches first (5 ft 10 in = 70 in), then multiply by 2.54: 70 × 2.54 = 177.8 cm.
| Height | Inches | Centimeters |
|---|---|---|
| 5′0″ | 60 | 152.4 |
| 5′2″ | 62 | 157.48 |
| 5′4″ | 64 | 162.56 |
| 5′6″ | 66 | 167.64 |
| 5′8″ | 68 | 172.72 |
| 5′10″ | 70 | 177.8 |
| 6′0″ | 72 | 182.88 |
| 6′2″ | 74 | 187.96 |
| 6′4″ | 76 | 193.04 |
Quick reference
| Metric | Imperial / US | Imperial / US | Metric |
|---|---|---|---|
| 1 cm | 0.393701 in | 1 in | 2.54 cm |
| 10 cm | 3.93701 in | 12 in (1 ft) | 30.48 cm |
| 1 m | 3.28084 ft | 1 yd | 0.9144 m |
| 10 m | 32.8084 ft | 10 ft | 3.048 m |
| 1 km | 0.621371 mi | 1 mi | 1.60934 km |
| 100 km | 62.1371 mi | 100 mi | 160.934 km |
For running, a 5K is 3.10686 miles, a 10K is 6.21371 miles, a half marathon (21.0975 km) is 13.1094 miles and a marathon (42.195 km) is 26.2188 miles.
Common mistakes
- Reading decimal feet as feet and inches. 5.5 ft is 5 ft 6 in, not 5 ft 5 in.
- Mixing up miles and nautical miles. A nautical mile is about 15% longer than a statute mile.
- Rounding too early. Using 2.5 cm per inch instead of 2.54 puts a 6 ft height out by almost 3 cm.