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Harris-Benedict BMR Calculator

Calculate your Basal Metabolic Rate using the revised Harris-Benedict equation.

Result

BMR (Harris-Benedict)
1,763 kcal/day

Uses the revised (1984) Harris-Benedict equation. Our BMR Calculator uses the newer Mifflin-St Jeor formula, generally considered more accurate for the modern population - the two typically differ by only a small percentage, but Harris-Benedict remains widely referenced and is offered here as an alternative.

About the Harris-Benedict BMR

The Harris-Benedict BMR Calculator estimates basal metabolic rate, the number of calories the body burns at complete rest, using the revised 1984 version of the Harris-Benedict equation. It is intended for anyone who wants a BMR estimate from this specific, long-established formula rather than a newer alternative like Mifflin-St Jeor. Enter sex, weight, height, and age to get a daily calorie estimate.

How It Works

The calculator applies one of two linear equations depending on sex, each combining weight in kilograms, height in centimeters, and age in years with fixed coefficients from the original Harris-Benedict regression analysis, revised in 1984. Weight and height both add to the estimate while age subtracts from it, reflecting that metabolic rate tends to decline somewhat with age even at a constant weight and height.

Men: BMR = 88.362 + (13.397 x weight in kg) + (4.799 x height in cm) - (5.677 x age in years). Women: BMR = 447.593 + (9.247 x weight in kg) + (3.098 x height in cm) - (4.330 x age in years).

Examples

Male example: 30 years, 75 kg, 175 cm

Plugging these values into the male equation returns a BMR of approximately 1,763 kcal per day.

Female example: 40 years, 65 kg, 165 cm

Plugging these values into the female equation returns a BMR of approximately 1,387 kcal per day.

Advantages

  • Applies a well-documented, historically significant formula exactly as published, useful for anyone who specifically wants a Harris-Benedict figure rather than a different BMR equation.
  • Uses sex-specific coefficients, avoiding the inaccuracy of applying a single unisex formula to both men and women.
  • Provides a quick reference point for comparison against BMR figures from other formulas or from metabolic testing.

Common Mistakes

  • Treating the BMR output as a total daily calorie target, when it reflects resting energy expenditure only and needs an activity multiplier applied separately to estimate total daily burn.
  • Entering height in inches or weight in pounds instead of the required centimeters and kilograms, which skews the result since the coefficients are calibrated to metric units.
  • Assuming Harris-Benedict and Mifflin-St Jeor will always return nearly identical numbers, when the two formulas use different coefficients and can diverge more noticeably at certain weight and height combinations.

Edge Cases to Watch For

  • The result is basal metabolic rate only, meaning calories burned at complete rest, with no activity multiplier applied; it is not a total daily calorie estimate on its own.
  • The formula is purely linear with no floor, so an unusual combination of high age with low weight and height could mathematically produce a very low result, since nothing in the equation prevents the age term from outweighing the weight and height terms.
  • This is the revised 1984 version of the equation, not the original 1919 version, and the site's separate BMR calculator uses the newer Mifflin-St Jeor formula instead, so the two tools can return slightly different numbers for identical inputs.

Common Use Cases

  • Someone who wants to compare a Mifflin-St Jeor BMR estimate against the older Harris-Benedict figure for the same inputs.
  • Someone researching or referencing historical BMR calculation methods for academic or professional purposes.
  • Someone building a calorie plan who wants a baseline resting energy figure before applying their own activity multiplier.
Written & fact-checked by the Calculateus TeamLast updated August 5, 2026How we verify our formulas

Frequently asked questions

Why do multiple different BMR formulas exist?

Each formula was developed from regression analysis of a specific study population at a specific point in time, and body composition, average activity levels, and measurement technology have changed since the original 1919 Harris-Benedict study - newer formulas like Mifflin-St Jeor (1990) were developed partly to better reflect a more contemporary population, though Harris-Benedict remains historically significant and still reasonably accurate for many people.

Related calculators

BMI CalculatorCalculate your Body Mass Index (BMI) and see which weight category you fall into.BMI Prime CalculatorCalculate BMI Prime - the ratio of your BMI to the upper limit of normal BMI (25).Calorie CalculatorEstimate your daily calorie needs to maintain, lose or gain weight.BMR CalculatorCalculate your Basal Metabolic Rate - calories burned at complete rest.

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Conclusion

The calculator reproduces the revised Harris-Benedict equation precisely, giving a resting calorie estimate grounded in one of the most widely referenced BMR formulas. Because it uses fixed sex-specific coefficients rather than a single blended formula, it produces different curves for men and women across the same weight, height, and age inputs.

References