Calorie Calculator

Estimate adult resting energy expenditure with the Mifflin–St Jeor equation and multiply it by a selected activity factor for an illustrative daily energy estimate.

Age

Sex coefficient used by equation

Weight (kg)

Height (cm)

Activity level

The 10% lower and higher figures are mathematical scenarios, not personalised intake prescriptions. Individual needs can differ.

About This Tool

What it does

Calculates estimated resting energy expenditure with the adult Mifflin–St Jeor equation, then applies the selected activity multiplier. It also displays simple ±10% mathematical scenarios.

Who it's for

Adults seeking a general planning estimate. It is not designed for children, pregnancy, breastfeeding, eating-disorder care, illness or clinical nutrition planning.

Your privacy

All calculations happen in your browser. No data is transmitted or stored anywhere.

How the estimate is produced

The Mifflin–St Jeor equation estimates resting energy expenditure from weight, height, age and a sex-specific coefficient. The selected activity factor is then multiplied by that estimate. Activity factors are broad assumptions, so the output is not a measured energy requirement.

Authoritative references

Reviewed 23 June 2026: Mifflin et al.: original resting-energy equation; US NIDDK: Body Weight Planner; World Health Organization: healthy diet.

Helpful guides

Body fat percentage vs BMICompare what each measure tells you and where each can mislead.Read guide →

Frequently Asked Questions

Which equation is used?

The calculator uses the adult Mifflin–St Jeor resting-energy equation and then multiplies the result by the selected activity factor.

What does the activity-adjusted total mean?

It is an illustrative daily energy estimate based on a broad activity multiplier. It is not a measured requirement and can differ from actual expenditure.

Are the 10% lower and higher figures recommendations?

No. They are simple mathematical scenarios provided for comparison, not personalised weight-loss, weight-gain or nutrition targets.

Who should not rely on this calculator?

It is not designed for children, pregnancy, breastfeeding, eating-disorder treatment, serious illness or clinical nutrition care. Seek qualified professional advice in those situations.