BMR & Calorie (TDEE) Calculator

Use this free online BMR calculator to estimate your Basal Metabolic Rate and Total Daily Energy Expenditure (TDEE) using the Mifflin-St Jeor equation. Enter your gender, weight, height, age, and activity level to find out how many calories your body needs each day. This tool is for general informational purposes only and is not a substitute for professional medical or nutritional advice.

How to Use the BMR Calculator

  1. Select your Gender from the dropdown.
  2. Enter your Weight (kg) and Height (cm).
  3. Enter your Age (years).
  4. Choose your Activity Level that best matches your weekly exercise routine.
  5. Click "Calculate BMR & TDEE" to see your BMR and daily calorie needs.

BMR and TDEE Explained

Your Basal Metabolic Rate is the energy your body uses in a day just to stay alive at rest: keeping your heart beating, breathing, maintaining body temperature and running your organs. For most people it accounts for the largest share of daily calorie use, more than exercise does.

Total Daily Energy Expenditure adds everything else: walking, climbing stairs, household work, your job and any workouts. The calculator estimates it by multiplying BMR by an activity factor. TDEE is the figure to use when planning meals, because it is roughly the number of calories at which your weight stays the same.

Worked Example

Take a 30-year-old man who weighs 70 kg and is 175 cm tall. Using the Mifflin-St Jeor equation for men:

BMR = (10 × 70) + (6.25 × 175) − (5 × 30) + 5 = 700 + 1,093.75 − 150 + 5 = 1,648.75 calories per day.

His TDEE then depends on the activity level he selects:

Activity levelMultiplierTDEE (calories/day)
Sedentary (little or no exercise)1.21,978.50
Light (exercise 1-3 days/week)1.3752,267.03
Moderate (exercise 3-5 days/week)1.552,555.56
Active (exercise 6-7 days/week)1.7252,844.09
Very Active (hard exercise daily)1.93,132.62

For comparison, a 28-year-old woman weighing 58 kg at 160 cm has a BMR of (10 × 58) + (6.25 × 160) − (5 × 28) − 161 = 1,279 calories, and a TDEE of about 1,759 calories with light activity (1,279 × 1.375).

Choosing the Right Activity Level

The activity factor makes a bigger difference to the final number than any other input, and most people overestimate it. A desk job with a one-hour commute by car or metro and no planned exercise is Sedentary, even if the day feels busy. A 30–45 minute brisk walk or gym session three or four times a week fits Light to Moderate. Reserve Active and Very Active for daily hard training or physically demanding work such as construction or farm labour. When unsure, pick the lower option and adjust after watching your weight for a few weeks.

Using Your TDEE for Weight Goals

  • To maintain weight, eat close to your TDEE.
  • To lose weight gradually, a common approach is to eat around 300–500 calories below TDEE, which for many people works out to roughly 0.25–0.5 kg of loss per week. The body adapts over time, so progress usually slows.
  • To gain weight or build muscle, a modest surplus of 250–500 calories above TDEE together with strength training is a typical starting point.
  • Recalculate after every few kilograms of change, because a lighter body has a lower BMR and TDEE.

Mifflin-St Jeor is one of the more reliable equations for the general adult population, but it is still an estimate. It does not know your muscle mass, so very muscular people may burn more than predicted and people with higher body fat may burn less. Thyroid conditions, some medicines, pregnancy and breastfeeding also change energy needs. For a diet plan, especially with diabetes or another medical condition, consult a doctor or registered dietitian.

Frequently Asked Questions

This calculator uses the Mifflin-St Jeor equation: for men, BMR = 10×weight(kg) + 6.25×height(cm) - 5×age + 5; for women, BMR = 10×weight(kg) + 6.25×height(cm) - 5×age - 161.

BMR is the number of calories your body burns at complete rest just to maintain basic functions. TDEE (Total Daily Energy Expenditure) multiplies BMR by an activity factor to estimate how many calories you burn in a full day, including exercise and daily movement.

Each activity level applies a different multiplier to your BMR, ranging from 1.2 for a sedentary lifestyle up to 1.9 for very intense daily exercise, so choosing the option closest to your real routine gives a more accurate TDEE.

Generally no. BMR is what your body needs at complete rest, and you are not at rest all day. Weight-loss targets are usually set below TDEE, not at or below BMR. Eating very little for long periods can cause muscle loss, fatigue and nutrient shortfalls, so large deficits should be supervised by a doctor or dietitian.

The equation subtracts 5 calories for every year of age, reflecting the gradual loss of muscle and changes in metabolism over the years. For example, the same 70 kg, 175 cm man would have a BMR of 1,648.75 at 30 and 1,598.75 at 40. Regular strength training helps preserve muscle and slows this decline.
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