The Harris-Benedict equation dates from 1918 and was revised by Roza and Shizgal in 1984. It is still widely used in clinical nutrition.
How to use the Harris-Benedict BMR Calculator
- Sex
- Age
- Weight
- Height
- Activity level
Results update as you type, and every field accepts the units shown in its menu.
How it works
Weight in kilograms, height in centimetres and age in years are entered into the sex-specific equation.
Inputs explained
| Field | What to enter |
|---|---|
| Sex | Choose one: Male, Female |
| Age | In years |
| Weight | Units: kg, lb, g, oz, st |
| Height | Units: cm, m, mm, in, ft |
| Activity level | Choose one: Sedentary, Light (1–3 days/week), Moderate (3–5 days/week), Very active (6–7 days/week) … |
Example values
How the main result changes when Age changes and everything else stays at the example values above:
| Age (years) | BMR (Harris-Benedict) (kcal/day) |
|---|---|
| 17.5 | 1,848 |
| 26.25 | 1,798 |
| 35 | 1,749 |
| 43.75 | 1,699 |
| 52.5 | 1,649 |
| 70 | 1,550 |
Health note: this calculator is for education and screening only and is not a diagnosis or treatment advice. Discuss your results with a qualified clinician.
Formula
Men: BMR = 88.362 + 13.397W + 4.799H − 5.677AWomen: BMR = 447.593 + 9.247W + 3.098H − 4.330AWorked example
Inputs — Sex: Male; Age: 35 years; Weight: 75 kg; Height: 178 cm; Activity level: Light (1–3 days/week).
Results — BMR (Harris-Benedict) = 1,749 kcal/day; Daily calories (TDEE) = 2,404 kcal/day; Mifflin–St Jeor BMR = 1,693 kcal/day.
Key terms
- BMR
- Basal metabolic rate, energy used at complete rest.
Frequently asked questions
Which equation is more accurate?
Studies generally find Mifflin–St Jeor slightly more accurate for modern adults.
Why do results differ?
They were fitted to different populations decades apart.
What formula does the Harris-Benedict BMR Calculator use?
Men: BMR = 88.362 + 13.397W + 4.799H − 5.677A.