Which BMR formula should I use?

Mifflin–St Jeor is commonly recommended for general use. If you know your body fat percentage, Katch–McArdle can be more personalized. The tool shows all four so you can compare.

Do you store my data?

No. Everything runs in your browser; nothing is uploaded.

What units can I use?

Use centimeters or feet/inches for height and kilograms or pounds for weight. Toggle units in the form.

Total Daily Energy Expenditure (TDEE) is your BMR multiplied by an activity factor. We provide a quick activity table for reference.

BMR Calculator — Mifflin–St Jeor, Harris–Benedict, Katch–McArdle & Schofield

Enter your details. All calculations run locally in your browser—nothing is uploaded.

Your details & options

Sex

Used by MSJ, Harris-Benedict, Schofield.

Age (years)

Height

Switch between centimeters and feet/inches.

Weight

Body Fat % (optional)

Used for Katch–McArdle (lean body mass).

Activity (for quick TDEE)

Formulas

Mifflin–St Jeor Harris–Benedict (revised) Katch–McArdle Schofield

Results are estimates. For medical advice, consult a clinician.

Results

Enter your details and click Calculate.

About the formulas

Basal Metabolic Rate (BMR) estimates how many calories your body burns at rest. This tool computes BMR using multiple research-backed equations:

Mifflin–St Jeor (1990): Often most accurate for general use.
Harris–Benedict (revised): Classic formula with updated coefficients.
Katch–McArdle: Uses lean body mass when body fat % is known.
Schofield: Uses age/sex-specific constants (commonly used by WHO/FAO).

Equations

Mifflin–St Jeor (men): \( \mathrm{BMR} = 10w + 6.25h - 5a + 5 \)
Mifflin–St Jeor (women): \( \mathrm{BMR} = 10w + 6.25h - 5a - 161 \)

Harris–Benedict (revised) (men): \( \mathrm{BMR} = 88.362 + 13.397w + 4.799h - 5.677a \)
Harris–Benedict (revised) (women): \( \mathrm{BMR} = 447.593 + 9.247w + 3.098h - 4.330a \)

Katch–McArdle: \( \mathrm{BMR} = 370 + 21.6 \times \mathrm{LBM} \), where \( \mathrm{LBM} = w \times (1 - \mathrm{bf}) \)

Schofield: \( \mathrm{BMR} = A \times w + B \) (A and B depend on age group & sex).

Here \(w\) is weight in kg, \(h\) is height in cm, \(a\) is age in years, and \(\mathrm{bf}\) is body fat fraction.

Frequently Asked Questions

Which formula should I use?

Mifflin–St Jeor is a solid default. If you know body fat %, Katch–McArdle personalizes the estimate using lean mass.

How do you compute TDEE?

TDEE = BMR × activity factor. We show a quick table using standard multipliers.

Is my data private?

Yes—everything runs locally in your browser. No uploads or storage.