UK weight-loss calculator
9 stone in kg
9 stone is 57.2 kg. Below: how that is worked out, and what it means at your height.
Updated
st lb = kg
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.
Stone and pounds to Kilograms
57.2 kg
9 st 0 lb converts to the figure on the left, exactly. Nothing in it is an approximation.
Converting 9 st
9 stone is 57.2 kg. A stone is exactly 14 pounds and a pound is exactly 0.45359237 kg, so 9 st is 126 lb, and 126 lb is 57.2 kg.
The halves either side
Scales and people rarely stop at whole stone. 8 st 7 lb is 54 kg and 9 st 7 lb is 60.3 kg, so a half stone either side of 9 st spans 54 to 60.3 kg.
What 9 stone means at different heights
Whether 9 stone is a lot depends on how tall you are. At 5 ft 0 in it is a BMI of 24.6, which the NHS calls healthy weight; at 6 ft 2 in the same weight is 16.2, which it calls underweight. It is inside the healthy range at 5 of the 8 heights here.
| Height | BMI | NHS category | From healthy range |
|---|---|---|---|
| 5 ft 0 in | 24.6 | Healthy weight | inside it |
| 5 ft 2 in | 23.1 | Healthy weight | inside it |
| 5 ft 4 in | 21.6 | Healthy weight | inside it |
| 5 ft 6 in | 20.4 | Healthy weight | inside it |
| 5 ft 8 in | 19.2 | Healthy weight | inside it |
| 5 ft 10 in | 18.1 | Underweight | 1.2 kg under |
| 6 ft 0 in | 17.1 | Underweight | 4.6 kg under |
| 6 ft 2 in | 16.2 | Underweight | 8.1 kg under |
Losing 5 to 20% of 9 stone
Weight-loss advice is usually quoted in percentages, which is hard to picture. From 9 stone, this is what each of those marks comes to.
| Reduction | Weight lost | New weight | In stone and pounds |
|---|---|---|---|
| 5% | 2.9 kg | 54.3 kg | 8 st 7.8 lb |
| 10% | 5.7 kg | 51.5 kg | 8 st 1.5 lb |
| 15% | 8.6 kg | 48.6 kg | 7 st 9.2 lb |
| 20% | 11.4 kg | 45.8 kg | 7 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
Very few people are a whole number of stone, and the one you want is usually next door.
For the conversion in the other direction, see kg to stone, or stone to pounds for the same weight in pounds alone. The BMI calculator takes your own height rather than the eight above.