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Calorie Calculator (BMR & TDEE)

Estimate your daily calorie needs with the Mifflin–St Jeor formula.

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About Health Calculator

BMI is a population screening figure and carries no information about body composition, so it misreads muscular and older bodies in opposite directions. All three outputs are estimates for planning, not a substitute for a clinician.

Estimate your daily calorie needs — both BMR and TDEE — using the well-regarded Mifflin–St Jeor formula from your age, height, weight and activity level. It is calculated privately in your browser.

Estimate your Body Mass Index, daily calorie needs using the proven Mifflin–St Jeor formula, and a pregnancy due date from your last menstrual period. It brings three common health estimates together so you can plan diet, fitness and milestones quickly.

These figures are informational estimates rather than medical advice — take decisions about your health with a clinician. Calorie targets especially are a starting point to adjust against real results, since activity level is self-reported and easy to overstate.

Learn how this works

Everyday Calculations & Conversions Made SimpleConvert units and time zones, and calculate age, BMI, discounts and loan EMIs — a plain-English guide with free in-browser tools.7 min read

Frequently asked questions

What is the difference between BMR and TDEE?

BMR is what you burn at complete rest — keeping your organs running. TDEE is BMR multiplied by an activity factor, so it covers everything you actually do in a day. TDEE is the number to work from when planning intake.

Which activity level should I choose?

Most people overestimate. A desk job with a few gym sessions a week is 'lightly active', not 'very active' — that tier is closer to physical work or daily hard training. If your weight is not moving as expected after a few weeks, an over-stated activity level is the usual reason.

How accurate is the estimate?

It is a population-level formula, so individuals commonly land within about 10% either side. Treat the number as a starting point, then adjust from what actually happens to your weight over two or three weeks.

Common Use Cases

  • •Setting a realistic daily calorie target instead of guessing
  • •Working out how much a change in training volume shifts your needs
  • •Sanity-checking a figure an app or tracker has given you

More Health Calculator tools

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