BMR Calculator

Estimate your Basal Metabolic Rate (BMR) and Daily Calorie Targets using standard formulas.

Weight (kg)

Height (cm)

Age (years)

Formula

Activity Multiplier

Activity Tiers Reference

Sedentary: 1.2x (Desk job, minimal activity)
Lightly Active: 1.375x (Light exercise 1-3 days)
Moderately Active: 1.55x (Moderate workout 3-5 days)
Very Active: 1.725x (Hard sports/exercise 6-7 days)

BMR (Basal Metabolic Rate)

1,649 kcal/day

Energy needed to sustain life at complete rest.

TDEE (Total Daily Energy Expenditure)

1,979 kcal/day

Total calories burned factoring in your activity level.

Daily Calorie Targets for Weight Goals

Goal Type	Daily Caloric Target	Adjustment
Maintain weight	1,979 kcal/day	0 kcal deficit
Mild weight loss (0.5 lb / 0.25 kg week)	1,729 kcal/day	-250 kcal deficit
Weight loss (1 lb / 0.5 kg week)	1,479 kcal/day	-500 kcal deficit
Extreme weight loss (2 lb / 1 kg week)	1,200 kcal/day	-1,000 kcal deficit
Mild weight gain (0.5 lb / 0.25 kg week)	2,229 kcal/day	+250 kcal surplus
Weight gain (1 lb / 0.5 kg week)	2,479 kcal/day	+500 kcal surplus

BMR and TDEE, Explained

Your Basal Metabolic Rate (BMR) is the minimum caloric energy required to sustain life-essential organs and tissues at complete rest. Once BMR is established, it is multiplied by an activity factor to compute your Total Daily Energy Expenditure (TDEE).

This calculator supports three distinct calculation formulas:

Mifflin-St Jeor: The current clinical standard for normal weight populations.
Revised Harris-Benedict: An update to the classical equation that incorporates modern stature models.
Katch-McArdle: Unlocks body composition based metabolic rates, particularly useful for highly muscular athletes.

Built and maintained by Meet Shah · Last updated 1 August 2026

What this tool is used for

Getting a baseline figure before deciding on an activity multiplier for a daily target.
Comparing how the estimate changes with weight, so a target can be revisited over time.
Understanding why two people of the same weight have different baseline needs.
Producing a starting number to discuss with a professional rather than guessing.
Seeing how much of a daily total is baseline rather than activity.

Frequently Asked Questions

What does BMR actually measure?: The energy needed at complete rest to run basic function — circulation, respiration, cell maintenance, brain activity. It is typically 60–70% of daily expenditure, which is why it dominates a calorie target far more than exercise does.
Which equation is most accurate?: Mifflin-St Jeor, which superseded Harris-Benedict and is what the Academy of Nutrition and Dietetics recommends. Katch-McArdle is better still when body fat percentage is known, because it works from lean mass rather than from total weight.
Why do two people with identical stats differ?: Because the equations cannot see body composition, thyroid function or genetics. Muscle costs more to maintain than fat, so the same height, weight, age and sex can span several hundred calories — which is why the estimate needs calibrating against results.
Is BMR the same as resting metabolic rate?: Nearly, and RMR is what is actually measured. True BMR requires an overnight fast, complete rest and thermal neutrality; RMR relaxes those conditions and reads about 10% higher. The terms are used interchangeably and the distinction is real.
Does metabolism slow with dieting?: Yes, beyond what weight loss alone predicts — adaptive thermogenesis. A lighter body costs less to run and the body additionally reduces expenditure, which is why a deficit calculated at the start becomes maintenance at a lower weight.

Common errors and gotchas

Treating the result as measured. It is a population-level estimate and individual variation is substantial.
Applying an activity multiplier that flatters a mostly sedentary week.
Mixing units between height and weight, which produces a plausible but wrong figure.
Using it as medical advice rather than a rough starting point.
Recalculating daily and reacting to noise, when the formula only moves as the inputs do.