BMR (Basal Metabolic Rate) is the calories your body needs at rest to sustain vital functions. It forms the baseline for daily calorie estimates.

Which BMR formula should I use?

Mifflin–St Jeor is the recommended modern formula; Revised Harris–Benedict is an alternative. This tool calculates both for comparison.

How do I estimate calories for weight loss?

Estimate your TDEE by applying an activity multiplier to your BMR. A 10–20% calorie deficit from TDEE is a common starting point for gradual weight loss.

BMR Calculator

Basal Metabolic Rate (BMR) & TDEE Calculator

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BMR & TDEE

Definitions and practical guidance for Basal Metabolic Rate, activity multipliers, and how to use calorie targets for planning weight change.

Basal Metabolic Rate (BMR)

BMR is the number of calories your body needs at rest to maintain vital functions (breathing, circulation, cell repair). It excludes calories burned by activity or digestion. BMR is a baseline — a foundation for estimating daily calorie needs.

Mifflin–St Jeor vs. Revised Harris–Benedict

The Mifflin–St Jeor formula (recommended) is widely used because it gives reliable results across diverse populations. The Revised Harris–Benedict is an alternative that also estimates BMR using weight, height, age and sex. This tool computes both so you can compare results and choose what fits you best.

Total Daily Energy Expenditure (TDEE)

TDEE multiplies BMR by an activity level multiplier to estimate typical daily calorie needs for weight maintenance. Choose the activity level that best matches your daily routine — from sedentary to extra active.

Calorie targets for goals

This calculator shows maintenance calories (TDEE) and sample calorie targets for gradual weight loss or gain. A common starting point is a 10–20% deficit for moderate weight loss and a 10–15% surplus for controlled muscle gain; always adapt to personal needs and consult a professional for medical advice.

Why exact inputs matter

Small differences in weight, height or age change BMR results — this calculator uses exact conversions and shows results with decimal precision so spreadsheet imports and tracking reconcile precisely.