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HEALTH CALCULATOR

Calorie Calculator

Estimate adult resting energy expenditure and daily maintenance calories with the Mifflin–St Jeor equation. Compare simple deficit and surplus scenarios.

Calculator

The Mifflin–St Jeor equation uses sex-specific constants.
years
kg
cm
YOUR RESULTS
Estimated maintenance calories1,979 kcal/day
Resting energy estimate
1,649 kcal/day
250 kcal/day below
1,729 kcal/day
500 kcal/day below
1,479 kcal/day
300 kcal/day above
2,279 kcal/day

This estimate applies the Mifflin–St Jeor resting-energy equation and your selected activity factor. Individual needs vary.

Daily energy estimates

  • Resting energy estimate1,649 kcal/day
  • Estimated maintenance calories1,979 kcal/day
  • 250 kcal/day below1,729 kcal/day
  • 500 kcal/day below1,479 kcal/day
  • 300 kcal/day above2,279 kcal/day

These are the same estimates shown in the results, not individual calorie recommendations.

Understanding your result

Resting energy is multiplied by the selected activity factor to estimate maintenance needs. Other figures are arithmetic offsets for comparison; individual response varies.

To compare weight with height separately, the BMI Calculator reports the adult screening range, which does not measure energy needs.

The formula

RMR = 10W + 6.25H − 5A + S

W is kilograms, H is centimetres, A is age, and S is +5 for the male constant or −161 for the female constant. Daily expenditure equals RMR times activity factor.

A moderately active 30-year-old

For 70 kg, 175 cm, age 30 using the male constant, RMR is 1,648.75 kcal/day. A 1.55 activity factor gives about 2,555.6 kcal/day.

How to use this calculator

  1. Choose units and the equation constant that applies.
  2. Enter age, weight, height, and typical activity.
  3. Calculate and treat scenarios as starting estimates.

Activity is the largest estimate

The equation estimates energy at rest from population averages. The activity category introduces more uncertainty.

Choose a typical week rather than the most active day.

Use trends rather than one exact number

Food labels, portions, metabolism, and activity estimates all contain error.

Medical conditions, pregnancy, medications, growth, and training can require individualized guidance.

Assumptions & limitations

What this calculation assumes

  • Adult age 19–100 and stable measurements; ages above the original study population are extrapolations.
  • Mifflin–St Jeor constants and fixed activity multipliers.
  • Deficit and surplus values are arithmetic comparisons.

What to keep in mind

  • This estimate is not a meal plan, diagnosis, or prescription.
  • The equation excludes pregnancy, illness, and adaptive changes.
  • Very low targets can be inappropriate.
  • The original Mifflin–St Jeor study included adults aged 19–78, so older-age estimates carry additional uncertainty.

Common questions

What is BMR versus maintenance?

Resting energy covers rest; maintenance multiplies it by activity.

Why are deficits not a weight-loss promise?

Expenditure and weight response vary over time.

Which activity level should I choose?

Use a typical long-term pattern, considering exercise and physical work.

Sources & further reading