BMI Calculator (Stone and Pounds)
Calculate your Body Mass Index using feet, inches, stone and pounds.
Your result
Updates as you type. Based on 2025/26 UK figures where relevant.
How this is worked out
BMI is weight in kg divided by height in metres squared. The NHS adult ranges are: under 18.5 underweight, 18.5–24.9 healthy, 25–29.9 overweight and 30 or more obese. BMI doesn't account for muscle, age or ethnicity.
Tips
- The NHS uses BMI as a screening tool, but waist measurement also matters.
- Estimates like BMR and body fat can vary by 5–10% from lab measurements.
- Track trends over weeks rather than day-to-day changes.
Guides for this calculator
More health and fitness calculators
Frequently asked questions
How does the bMI Calculator (Stone and Pounds) work?
BMI is weight in kg divided by height in metres squared. The NHS adult ranges are: under 18.5 underweight, 18.5–24.9 healthy, 25–29.9 overweight and 30 or more obese. BMI doesn't account for muscle, age or ethnicity.
Is this medical advice?
No. These tools give general estimates. For medical advice, speak to your GP, pharmacist or NHS 111.
Can I use these for children?
No. Children's BMI and health measures use age- and sex-specific charts. Use the NHS healthy weight calculator for children.
Why use stone and pounds?
Many people in the UK still think in stone and pounds, so we accept those units and show metric too.
This calculator gives an estimate for general information. It isn't financial, tax, legal or medical advice. Check official figures on GOV.UK or NHS.uk, or speak to a qualified adviser.