Resting Metabolic Rate Calculator

Work out resting metabolic rate instantly with clear inputs, formula shown and shareable results.

About Resting Metabolic Rate Calculator

Converts measured oxygen consumption into energy expenditure by indirect calorimetry, using the caloric equivalent of oxygen for the measured respiratory quotient.

Formula

Indirect calorimetry

Energy (kcal/min) = VO2 (L/min) x caloric equivalent of oxygen, which runs from 4.686 kcal/L at RQ 0.707 to 5.047 kcal/L at RQ 1.00

Worked example

With the default values below, Resting Metabolic Rate Calculator returns Resting metabolic rate of 1,750.4. Change any input above and every figure here is recalculated in your browser.

Inputs used

Measured oxygen consumptionaccepts 0.05–2 L/min: 0.25 L/min
Weightaccepts 20–300 kg: 70 kg
Respiratory quotientaccepts 0.7–1: 0.85

Results

Resting metabolic rate: 1,750.4 kcal/day
Energy expenditure: 72.93 kcal/h
Oxygen uptake: 3.57 mL/kg/min
Metabolic equivalents: 1.020 MET

Step by step

1Values used
2Indirect calorimetry
3Resting metabolic rate= 1,750.4 kcal/day
4Energy expenditure= 72.93 kcal/h
5Oxygen uptake= 3.57 mL/kg/min
6Metabolic equivalents= 1.020 MET

Assumptions and limits

The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 3 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
Educational estimate only. Not a substitute for professional clinical judgement, and must not be used to make treatment or dosing decisions.
This is an estimate for general information and not professional medical advice. See the full disclaimer for the limits that apply to this kind of calculator.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Educational estimate only. Not a substitute for professional clinical judgement, and must not be used to make treatment or dosing decisions.

Frequently Asked Questions

How does this differ from a prediction equation?

It measures energy expenditure directly rather than estimating it from body size, so it captures individual variation.

Why does the respiratory quotient matter?

Fat and carbohydrate release different energy per litre of oxygen, so the conversion factor shifts with substrate use.