Basal Metabolic Rate (BMR) is the number of calories your body needs at complete rest to maintain basic functions like breathing, circulation and cell production.

How is BMR different from TDEE?

BMR is your resting calorie burn. TDEE (Total Daily Energy Expenditure) includes BMR plus all activity — walking, running, working, etc. Runners need to eat to their TDEE to maintain weight.

Which BMR formula is most accurate?

The Mifflin-St Jeor equation (used here) is considered the most accurate for most adults. It accounts for weight, height, age and sex.

How many calories should a runner eat?

It depends on training volume, but most recreational runners need 2,000-3,000 kcal/day. Marathon trainers may need 2,500-4,000 kcal/day during peak weeks.

RunCalcs

BMR Calculator — Basal Metabolic Rate for Runners

Calculate your basal metabolic rate and daily calorie needs as a runner.

Weight

Height

Age

Sex

Activity Level

How We Calculate This

The Mifflin-St Jeor Equation

This calculator uses the Mifflin-St Jeor equation, considered the gold standard for BMR estimation:

Men: BMR = 10 x weight(kg) + 6.25 x height(cm) - 5 x age + 5

Women: BMR = 10 x weight(kg) + 6.25 x height(cm) - 5 x age - 161

TDEE is then calculated by multiplying BMR by an activity factor (1.2 to 1.9). The runner macro split follows a 55/20/25 carb/protein/fat ratio.

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates. Always consult a coach or medical professional for personalised training advice.