Quick answer: 5’10” is 177.8 cm, and 11 stone is 69.9 kg. And no, you cannot type 5.10 into a normal calculator to get there.
Heights in feet, weights in stone or pounds: they show up on dating profiles, sports pages, medical forms and gym machines. Here is the translation, and the trap.
The 5.10 trap
Feet and inches are base 12: 5’10” means 5 feet plus 10 inches. Typed as a decimal, 5.10 feet is about 155 cm, which would make most basketball players rather short. The right maths: 5 × 30.48 + 10 × 2.54 = 177.8 cm (the foot is exactly 30.48 cm and the inch 2.54 cm, per the NIST definitions). Any conversion that treats the apostrophe as a decimal point produces confident nonsense.
Height chart
| Feet & inches | Centimetres |
|---|---|
| 5’2” | 157.5 cm |
| 5’4” | 162.6 cm |
| 5’6” | 167.6 cm |
| 5’8” | 172.7 cm |
| 5’10” | 177.8 cm |
| 6’0” | 182.9 cm |
| 6’2” | 188 cm |
| 6’5” | 195.6 cm |
Weight: pounds and stone
The US weighs in pounds, the UK often in stone: 1 stone = 14 lbs = 6.35 kg.
| Pounds | Stone | Kilograms |
|---|---|---|
| 120 lbs | 8 st 8 | 54.4 kg |
| 140 lbs | 10 st | 63.5 kg |
| 154 lbs | 11 st | 69.9 kg |
| 168 lbs | 12 st | 76.2 kg |
| 180 lbs | 12 st 12 | 81.6 kg |
| 200 lbs | 14 st 4 | 90.7 kg |
Rule of thumb: pounds to kilograms, divide by 2.2. Stone to kilograms, multiply by 6.35.
A profile says 5'10″. How tall is that?
5'10″ is 5 feet + 10 inches = 5 × 30.48 + 10 × 2.54 = 177.8 cm. Typing 5.10 as a decimal gives 155 cm, the classic trap.
Compound units are exactly what the app is for
Conversion Calculator reads feet and inches together, the way people actually write them, and gives you centimetres, metres, stone and kilograms at once, offline. It is the same trick it plays on 2ft6 shelves and 55 inch TV screens: type it once, read every unit.
Get the app free and never mistype 5.10 again.