Mifflin-St Jeor BMR Calculator
Calculate your Basal Metabolic Rate using the most accurate modern equation.
Your Estimated BMR
1,650 kcal/day
This is the number of calories your body burns at complete rest.
Daily Energy Needs (TDEE)
| Activity Level | Calories / Day |
|---|
Basal Metabolic Rate: The Mifflin-St Jeor Formula
Your Basal Metabolic Rate (BMR) represents the amount of energy (in calories) your body needs to function while at complete rest. This includes vital processes such as breathing, blood circulation, cell production, and nutrient processing.
Why use the Mifflin-St Jeor Equation?
Introduced in 1990, the Mifflin-St Jeor equation is widely considered by the American Dietetic Association to be the most accurate standard for calculating BMR in modern populations. It is generally preferred over the older Harris-Benedict equation, which often overestimates caloric needs.
The Formula Breakdown
The math relies on four key variables: weight, height, age, and gender. The formulas are as follows:
For Men:
BMR = (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) + 5
BMR = (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) + 5
For Women:
BMR = (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) – 161
BMR = (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) – 161
Calculation Example
Consider a 35-year-old female who weighs 65 kg and is 170 cm tall.
- Weight Component: 10 × 65 = 650
- Height Component: 6.25 × 170 = 1,062.5
- Age Component: 5 × 35 = 175
- Gender Adjustment: -161
Calculation: 650 + 1,062.5 – 175 – 161 = 1,376.5 Calories/day
From BMR to TDEE
While BMR tells you what you burn at rest, your Total Daily Energy Expenditure (TDEE) accounts for physical activity. The calculator above estimates this by applying standard activity multipliers ranging from 1.2 (sedentary) to 1.9 (extra active).