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Health

BMR Calculator

Estimate your Basal Metabolic Rate (BMR) and daily calorie needs (TDEE) with the Mifflin–St Jeor or Harris–Benedict equations. Choose your units, select an activity level, and optionally set a goal to see estimated calories. All calculations run locally in your browser.

Basal Metabolic Rate (BMR)
Client-side onlyNo data leaves your browser
Method

Mifflin–St Jeor is widely used for resting energy needs; Harris–Benedict is a classic alternative.

Units
Metric • Client-side
Sex & Age
years
Height
cm

Quick adjust: 178 cm

Weight
kg

Quick adjust: 75 kg

Activity & Goal

Results

Mifflin–St JeorActivity ×1.375
Summary
  • Sex & Age: male, 30 y
  • Height: 178 cm
  • Weight: 75 kg
  • BMR: 1718 kcal/day
  • TDEE: 2362 kcal/day
  • Goal Calories: ~2362 kcal/day (maintain)

BMR is the energy your body needs at rest. TDEE ≈ BMR × activity multiplier.

Interpretation

Use goal calories as a starting point. Adjust by 100–200 kcal and track body weight and energy levels weekly. Recalculate if your weight or activity changes.

These are estimates, not prescriptions. For medical or athletic targets, consult a qualified professional.

How to Use the BMR Calculator

This free, client-side BMR Calculator estimates your Basal Metabolic Rate and Total Daily Energy Expenditure (TDEE). Choose a formula, enter your stats, and select an activity level to see daily calorie needs for maintenance, weight loss, or weight gain.

  1. Pick a formula: Mifflin–St Jeor (default) or Harris–Benedict (revised).
  2. Select units: Use Metric (cm, kg) or Imperial (ft/in, lb). You can switch anytime; values convert automatically.
  3. Enter sex & age: These influence BMR in both formulas.
  4. Enter height & weight: Provide accurate measurements for best estimates.
  5. Choose activity level: Sedentary through Extra Active sets your TDEE multiplier.
  6. Set a goal: Maintain, mild loss/gain (~10%), or loss/gain (~20%) to estimate target daily calories.
  7. Copy or reset: Use Copy to save results or Reset to start over.

Formulas

  • Mifflin–St Jeor (kcal/day):
    Male: BMR = 10·kg + 6.25·cm − 5·age + 5
    Female: BMR = 10·kg + 6.25·cm − 5·age − 161
  • Harris–Benedict (revised, kcal/day):
    Male: BMR = 13.397·kg + 4.799·cm − 5.677·age + 88.362
    Female: BMR = 9.247·kg + 3.098·cm − 4.330·age + 447.593
  • TDEE: TDEE = BMR × activity multiplier

Activity Multipliers

  • Sedentary: ×1.2 — little/no exercise
  • Light: ×1.375 — 1–3 days/week
  • Moderate: ×1.55 — 3–5 days/week
  • Active: ×1.725 — 6–7 days/week
  • Extra Active: ×1.9 — physical job + training

FAQ

What’s the difference between BMR and TDEE?

BMR is the energy your body needs at rest. TDEE accounts for daily activity (BMR multiplied by an activity factor) and better reflects maintenance calories.

Are these numbers exact?

They’re estimates. Track body weight and adjust calories if progress stalls or moves too quickly.

Is my data private?

Yes—everything runs client-side. No data is uploaded or stored on a server.

Disclaimer: This calculator is for educational purposes only and isn’t a medical recommendation. Consult a qualified professional for personalized guidance.