BMI & Calorie Calculator
Calculate your BMI and estimated daily calorie needs to maintain, lose or gain weight.
Frequently asked questions
Is this tool free?
Yes. Calchemy tools are free to use in your browser.
Is my data uploaded?
No. The tools are designed to run locally in your browser unless clearly stated otherwise.
Is this medical advice?
No. BMI and calorie estimates are general guides only. BMI doesn't account for muscle mass, bone density or body composition, and calorie needs vary by individual. Speak to a doctor or dietitian for personalised advice.
How is the calorie estimate worked out?
It uses the Mifflin-St Jeor formula to estimate your resting metabolic rate, then multiplies it by an activity factor to estimate total daily calories, with a common 500 calorie/day guide for a roughly 0.5kg/week change.