Free tool
BMI & calorie (TDEE) calculator
Work out your BMI and an estimate of the calories your body uses each day, in US or metric units. It's a starting point for a conversation with your doctor, not a health assessment.
Your results
Enter your age, height and weight to see your results.
Educational estimate, not medical advice. Talk to your doctor before making changes, especially if you have a health condition, take medication, or are pregnant.
How this works
BMI is your weight divided by your height squared: 703 × pounds ÷ inches², or kilograms ÷ meters². We round it to one decimal place and use that rounded number to pick the CDC adult range, so 24.95 becomes 25.0, the overweight range.
Maintenance calories (TDEE) use the Mifflin-St Jeor equation for resting energy (10 × kg + 6.25 × cm − 5 × age, then +5 for men or −161 for women), multiplied by your activity factor (1.2 to 1.9), and rounded to the nearest 10 calories.
Gradual pace examples are about 250 and about 500 calories below that estimate. We never show an example below 1,200 calories a day for women or 1,500 for men.
Limitations
- BMI is a screening measure, not a diagnosis, and doesn't measure body fat directly.
- Calorie equations are based on averages; your real needs may differ.
- Adult BMI ranges don't apply under age 20, and calorie examples aren't shown under 18.
- The sex option only selects the equation; it doesn't capture every body.
- Not suitable during pregnancy or breastfeeding, or as a substitute for advice from your doctor or a registered dietitian.
Privacy
Tool inputs stay on your device. Everything is calculated in your browser; nothing you enter is sent to us or stored, apart from optional preferences (such as units or your last schedule) saved in your own browser.
Frequently asked questions
How to calculate BMI?
BMI uses weight and height in a mathematical ratio: weight in kilograms divided by height in meters squared. With pounds and inches, a conversion factor is used. It is a screening measure, not a diagnosis, and it does not describe your full health, body composition or individual nutritional needs.
How to calculate BMI with pounds and inches?
Divide your weight in pounds by your height in inches squared, then multiply by 703 to calculate BMI. Enter your full height in inches, not just the inches after your feet measurement. The number is a screening estimate only; it does not account for all differences in body composition.
How accurate are TDEE calculators?
TDEE calculators provide estimates based on equations and broad activity categories, not a measurement of your individual energy use. Different assumptions can produce different results. Use the number as educational context rather than an exact eating target, and ask a qualified healthcare professional about personal nutrition needs or persistent concerns.
Why can't I lose weight?
There is no single explanation that applies to everyone, and a website cannot identify yours. Weight is influenced by eating patterns, activity, sleep, life circumstances and other factors. If you are concerned about unexpected changes or persistent difficulty, discuss your situation with your doctor rather than following increasingly restrictive advice.
How much exercise do I need a week?
The CDC describes a general adult activity framework that includes aerobic movement and muscle-strengthening activities. That framework is not an individual exercise prescription. Choose activities appropriate to your current ability, start with what feels manageable, and ask your doctor about any limitations before beginning, especially with symptoms or a medical condition.
Sources
Last reviewed by the Body Reset Guides editorial team