# BMR Calculator

> Estimate basal metabolic rate with Mifflin–St Jeor, revised Harris–Benedict, or Katch–McArdle and view activity-adjusted daily energy needs.

Page: https://askcalculators.com/calculator/bmr-calculator/
Definition: https://askcalculators.com/calculator/bmr-calculator/definition.json
JSON Schema: https://askcalculators.com/calculator/bmr-calculator/schema.json
Version: 2.0.0
Maintained by: AskCalculators (software project; not a credentialed reviewer)
Qualified review: pending. Automated checks do not establish professional approval.
Page status: Live
Review status: Pending

## Use
Open the calculator page and enter values. Query-string parameters can restore and bookmark a calculation.
Example: https://askcalculators.com/calculator/bmr-calculator/?unitSystem=metric&sex=male&age=30&formula=mifflin&weightKg=70&heightCm=175&activity=moderate&energyUnit=kcal

## Inputs
- unitSystem: Units; type=select; required; default=metric; values=metric|imperial
- sex: Sex used by equation; type=select; required; default=male; values=male|female
- age: Age; type=number; required; default=30; min=13; max=120
- formula: BMR equation; type=select; required; default=mifflin; values=mifflin|harris|katch
- weightKg: Weight; type=number; required; default=70; min=1; max=500; showWhen=unitSystem:metric
- heightCm: Height; type=number; required; default=175; min=50; max=300; showWhen=unitSystem:metric
- weightLb: Weight; type=number; required; default=154; min=2; max=1100; showWhen=unitSystem:imperial
- feet: Height feet; type=number; required; default=5; min=1; max=9; showWhen=unitSystem:imperial
- inches: Height inches; type=number; required; default=9; min=0; max=11.9; showWhen=unitSystem:imperial
- bodyFatPercent: Body fat; type=percent; optional; default=20; min=1; max=79; showWhen=formula:katch
- activity: Activity level; type=select; required; default=moderate; values=sedentary|light|moderate|active|veryActive|extraActive
- energyUnit: Energy display; type=select; required; default=kcal; values=kcal|kj

## Outputs
- bmr: Basal metabolic rate; format=number; primary
- sedentary: Sedentary daily need; format=number
- moderate: Moderate-activity daily need; format=number
- veryActive: Very-active daily need; format=number
- equation: Equation used; format=text

## Formula
Mifflin: 10W + 6.25H − 5A + s; revised Harris–Benedict uses sex-specific coefficients; Katch–McArdle: 370 + 21.6 × lean mass (kg).

## Rules
- Empty optional inputs are undefined, not zero.
- Hidden conditional inputs are ignored.
- Do not invent missing required inputs.

Notice: BMR and activity multipliers estimate energy use; individual metabolism and medical needs vary.