---
title: BMR & TDEE Calculator (Mifflin-St Jeor) – Per Day and Week · Weekfuel
url: https://weekfuel.app/en/bmr-calculator/
lang: en
updated: 2026-11-02
---

# BMR & TDEE calculator (Mifflin-St Jeor)

Your BMR is the energy your body needs at complete rest. Add activity and you get your TDEE – per day and per week.

**In short:** **Mifflin-St Jeor equation:** BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age (years) + 5 for men, or − 161 for women. Multiply your BMR by an activity factor (1.2 to 1.9) to get your TDEE.

*This calculator needs JavaScript. The formula is right below, so you can also work it out yourself.*

**BMR (basal metabolic rate):** The energy your body uses at rest for breathing, circulation, organs and body temperature. For most people it's the largest part of daily energy use.

**TDEE (total daily energy expenditure):** Your total daily burn: BMR plus energy for movement, exercise and digestion.

## Worked example

A 32-year-old woman, 170 cm (5'7"), 75 kg (165 lb):

10 × 75 + 6.25 × 170 − 5 × 32 − 161 = 750 + 1,062.5 − 160 − 161 = **1,491.5 calories** BMR. Lightly active (factor 1.375) that's about **2,051 calories** per day or **14,357 calories** per week.

## Activity factors

| Activity | Factor |
|---|---|
| sedentary | 1.2 |
| lightly active | 1.375 |
| moderately active | 1.55 |
| very active | 1.725 |
| extremely active | 1.9 |

These factors are approximations. If Weekfuel counts your steps, choose a lower factor so movement isn't counted twice.

## Why Mifflin-St Jeor?

In a systematic review of prediction equations, Mifflin-St Jeor most often predicted resting metabolic rate within ±10% of measured values in healthy adults (Frankenfield et al., 2005). Weekfuel uses the same equation.

## Frequently asked questions

### How accurate is a calculated BMR?

Formulas give estimates. For most people Mifflin-St Jeor lands within about 10% of a measured value; for individuals it can be more. Your weight trend shows whether the numbers work for you.

### What's the difference between BMR and TDEE?

BMR covers rest only. TDEE adds movement, exercise and digestion.

### Should I eat below my BMR?

To lose weight you eat below your TDEE, not necessarily below your BMR. Very low intake over longer periods should be medically supervised.

## Sources

- Mifflin MD, St Jeor ST et al. *Am J Clin Nutr* 1990;51(2):241–247. [PubMed 2305711](https://pubmed.ncbi.nlm.nih.gov/2305711/)
- Frankenfield D, Roth-Yousey L, Compher C: Comparison of predictive equations for resting metabolic rate in healthy nonobese and obese adults: a systematic review. *J Am Diet Assoc* 2005;105(5):775–789. [PubMed 15883556](https://pubmed.ncbi.nlm.nih.gov/15883556/)

## Keep reading

- [Calorie deficit calculator](https://weekfuel.app/en/calorie-deficit-calculator/)
- [Steps & deficit](https://weekfuel.app/en/steps-deficit/)
- [Weekly budget](https://weekfuel.app/en/weekly-budget/)

## Your week at a glance – automatically.

Weekfuel recalculates your weekly budget every day: meals by photo, steps from Apple Health, a trend instead of daily scale drama.

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