UK weight-loss calculator
81 kg in stone and pounds
81 kilograms is 12 st 10.6 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
12 st 10.6 lb
81 kg converts to the figure on the left, exactly. Nothing in it is an approximation.
Converting 81 kg
81 kilograms is 12 st 10.6 lb. A stone is 14 pounds and a kilogram is about 2.2046 pounds, so 81 kg is 178.6 lb, which is 12 whole stone with 10.6 lb left over.
Most converters stop at a decimal stone, which is not a unit anybody says out loud. 12 st 10.6 lb is the form you would use. In pounds alone it is 178.6 lb.
Between which whole stone
81 kg is 10.6 lb past 12 stone and 3.4 lb short of 13. 12 st exactly is 76.2 kg; 13 st is 82.6 kg. If you weigh yourself in stone, those are the two numbers either side of you.
What 81 kg means at different heights
Whether 81 kg is a lot depends entirely on how tall you are. At 5 ft 0 in it is a BMI of 34.9, which the NHS calls obese (class 1). At 6 ft 2 in the same weight is 22.9, which it calls healthy weight. It is inside the healthy range at 2 of the 8 heights below.
| Height | BMI | NHS category | From healthy range |
|---|---|---|---|
| 5 ft 0 in | 34.9 | Obese (class 1) | 23.1 kg over |
| 5 ft 2 in | 32.7 | Obese (class 1) | 19.2 kg over |
| 5 ft 4 in | 30.6 | Obese (class 1) | 15.1 kg over |
| 5 ft 6 in | 28.8 | Overweight | 11.0 kg over |
| 5 ft 8 in | 27.2 | Overweight | 6.6 kg over |
| 5 ft 10 in | 25.6 | Overweight | 2.2 kg over |
| 6 ft 0 in | 24.2 | Healthy weight | inside it |
| 6 ft 2 in | 22.9 | Healthy weight | inside it |
The last column is the gap to the nearest edge of the healthy band. At 5 ft 0 in, 81 kg is 23.1 kg over; by 6 ft 0 in it is inside it. A few inches of height moves that figure more than most people expect.
Losing 5 to 20% of 81 kg
Weight-loss advice is usually quoted in percentages, which is hard to picture. From 81 kg, this is what each of those marks comes to.
| Reduction | Weight lost | New weight | In stone and pounds |
|---|---|---|---|
| 5% | 4.1 kg | 77 kg | 12 st 1.6 lb |
| 10% | 8.1 kg | 72.9 kg | 11 st 6.7 lb |
| 15% | 12.2 kg | 68.9 kg | 10 st 11.8 lb |
| 20% | 16.2 kg | 64.8 kg | 10 st 2.9 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.
- 79 kg in stone12 st 6.2 lb
- 80 kg in stone12 st 8.4 lb
- 82 kg in stone12 st 12.8 lb
- 83 kg in stone13 st 1 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.