100 Pounds to KG
100 pounds is 45.36 kilograms, which works out to 45.3592 kg before rounding. To convert lbs to kg by hand, multiply the weight by 0.453592.
In traditional UK units, 100 pounds is 7 stone 2 pounds, or 7.14 stone in decimal form.
For all pound-to-kilogram conversions, see our full kg to pounds & pounds to kg converter.
Also: 7 stone 2 pounds · 7.14 stone · Convert 100 lbs to stone →
Result
Height & Health Context
At 100 pounds, which is 45.36 kg, the healthy weight range applies only to very short adults. At 5ft 0in the BMI is 19.6, healthy. At 5ft 2in the BMI is 18.4, just below the healthy threshold of 18.5 and therefore underweight. At 5ft 4in and above, 100 pounds falls clearly below the healthy BMI range. This weight comes up most often for children, teenagers, or adults of very petite stature, and for those groups the adult table is only a rough guide.
- 5ft 0in (152 cm): BMI is 19.6 (Healthy weight range)
- 5ft 2in (157 cm): BMI is 18.4 (just under the healthy threshold)
- 5ft 4in+ (163 cm+): falls below the usual adult BMI range
In my experience this conversion gets searched by three kinds of people: someone whose scale, app or allowance quotes pounds and wants kilograms; someone tracking a 100-pound change, which is 45.36 kg or 7 stone 2 pounds; and parents checking a child's weight against a kg-only chart. For adults, 100 pounds needs height context: at 5ft 0in the BMI is 19.6, while at 5ft 6in it is 16.1. Children and teenagers should be assessed using age- and sex-specific growth-chart information rather than adult BMI categories.
BMI by Height for 100 Pounds
| Height | Weight (kg) | BMI | BMI Screening Context |
|---|---|---|---|
| 5ft 0in (152cm) | 45.36 kg | 19.6 | Healthy Weight |
| 5ft 2in (157cm) | 45.36 kg | 18.4 | Underweight |
| 5ft 4in (163cm) | 45.36 kg | 17.1 | Underweight |
| 5ft 6in (168cm) (UK avg) | 45.36 kg | 16.1 | Underweight |
| 5ft 8in (173cm) | 45.36 kg | 15.2 | Underweight |
| 5ft 10in (178cm) | 45.36 kg | 14.3 | Underweight |
| 6ft 0in (183cm) | 45.36 kg | 13.5 | Underweight |
| 6ft 2in (188cm) | 45.36 kg | 12.8 | Underweight |
BMI varies significantly by height. Check your exact BMI →
Weights Close to 100 Pounds
Frequently Asked Questions
What is 100 pounds in kg?
100 pounds is 45.36 kg. Multiply 100 by 0.453592 to get 45.359 kg, which rounds to 45.36 kg.
What is 100 lbs in stone?
100 pounds is 7 stone 2 pounds. In decimal stone that is 7.14 stone.
Is 100 pounds underweight for an adult?
For most adults of typical UK height, yes. At 5ft 2in the BMI is 18.4, just below the healthy threshold, while at 5ft 0in it is 19.6, which is healthy.
At 5ft 2in or taller, 100 pounds falls below the healthy BMI range of 18.5 to 24.9.
What is 100 lbs in kg and stone?
100 pounds is 45.36 kg and 7 stone 2 pounds. In decimal stone that is 7.14 stone.
Is 100 pounds the same as 7 stone?
No. 100 pounds is 7 stone 2 pounds, which is 2 pounds over 7 stone.
7 stone exactly is 98 pounds, so 100 lbs sits just above the 7 stone mark.