UK weight-loss calculator
42 kg in stone and pounds
42 kilograms is 6 st 8.6 lb. Below: how that is worked out, and what it means at your height.
Updated
kg = st lb
Displayed values are rounded for readability, but the arithmetic uses the full precision of the internationally defined factors, a pound is exactly 0.45359237 kg and a stone is exactly 14 pounds, so converting back and forth will not drift.
Kilograms to Stone and pounds
6 st 8.6 lb
42 kg converts to the figure on the left, exactly. Nothing in it is an approximation.
Converting 42 kg
42 kilograms is 6 st 8.6 lb. A stone is 14 pounds and a kilogram is about 2.2046 pounds, so 42 kg is 92.6 lb, which is 6 whole stone with 8.6 lb left over.
Most converters stop at a decimal stone, which is not a unit anybody says out loud. 6 st 8.6 lb is the form you would use. In pounds alone it is 92.6 lb.
Between which whole stone
42 kg is 8.6 lb past 6 stone and 5.4 lb short of 7. 6 st exactly is 38.1 kg; 7 st is 44.5 kg. If you weigh yourself in stone, those are the two numbers either side of you.
What 42 kg means at different heights
At none of the heights below does 42 kg fall inside the range the NHS calls a healthy weight. It reads as underweight at 5 ft 0 in and underweight at 6 ft 2 in, a BMI of 18.1 down to 11.9.
| Height | BMI | NHS category | From healthy range |
|---|---|---|---|
| 5 ft 0 in | 18.1 | Underweight | 0.9 kg under |
| 5 ft 2 in | 16.9 | Underweight | 3.8 kg under |
| 5 ft 4 in | 15.9 | Underweight | 6.8 kg under |
| 5 ft 6 in | 15.0 | Underweight | 9.9 kg under |
| 5 ft 8 in | 14.1 | Underweight | 13.1 kg under |
| 5 ft 10 in | 13.3 | Underweight | 16.4 kg under |
| 6 ft 0 in | 12.6 | Underweight | 19.8 kg under |
| 6 ft 2 in | 11.9 | Underweight | 23.3 kg under |
42 kg sits below the healthy range at every height here, by 0.9 kg at 5 ft 0 in widening to 23.3 kg at 6 ft 2 in.
Losing 5 to 20% of 42 kg
Weight-loss advice is usually quoted in percentages, which is hard to picture. From 42 kg, this is what each of those marks comes to.
| Reduction | Weight lost | New weight | In stone and pounds |
|---|---|---|---|
| 5% | 2.1 kg | 39.9 kg | 6 st 4 lb |
| 10% | 4.2 kg | 37.8 kg | 5 st 13.3 lb |
| 15% | 6.3 kg | 35.7 kg | 5 st 8.7 lb |
| 20% | 8.4 kg | 33.6 kg | 5 st 4.1 lb |
The weight loss calculator estimates how long reaching one of those could take at a safe pace, and the weight loss percentage calculator works the other way round, turning weight already lost into a percentage.
BMI is a screening measure, not a diagnosis, and it says nothing on its own about how healthy you are. It does not know how much of you is muscle, and the thresholds are lower for some family backgrounds. What your BMI does and does not say.
The values either side
Scales rarely land on a whole number, and the one you want is often a kilogram either way.
- 40 kg in stone6 st 4.2 lb
- 41 kg in stone6 st 6.4 lb
- 43 kg in stone6 st 10.8 lb
- 44 kg in stone6 st 13 lb
For the conversion in the other direction, or for the full chart, see stone to kg and the kg to stone converter. To put this weight to work, the BMI calculator takes your own height rather than the eight above.