Free · no signup · adults 18+

A calorie target you can inspect, not just accept.

Estimate maintenance calories, a starting goal, protein, carbs, fat, and water. See the assumptions before deciding what to do next.

Calculator

Get your starting estimate

Results stay in your browser until you choose to continue.

1. Your starting point

The published equation uses physiological male and female coefficients.

years
cm
2. Your usual activity

Choose the level that best represents an average week, not your busiest day.

3. Your goal

The result is a starting planning estimate, not a promise of weekly weight change.

Free, no signup. Designed for adults age 18+; not for pregnancy or breastfeeding.

Your result

A useful starting point, with the assumptions shown.

You will get estimated resting energy, maintenance calories, a calorie target, macros, and water.

What the calculator does

Four steps, with no hidden precision.

  1. 1

    Estimate resting energy

    Mifflin–St Jeor estimates the energy an adult body uses at rest from sex, age, height, and weight.

  2. 2

    Apply an activity range

    Your activity choice turns resting energy into an estimated maintenance range. It is an assumption, not a measurement.

  3. 3

    Add the goal

    A modest deficit, maintenance target, or surplus creates a starting calorie plan with a safety floor.

  4. 4

    Set macro planning targets

    Protein and fat are set from body weight and goal; carbohydrates use the remaining planned energy.

Important limits

Useful for planning. Not a diagnosis.

  • Population equations can be meaningfully wrong for an individual.
  • Activity labels are broad and people often move differently from week to week.
  • Medication, health conditions, pregnancy, breastfeeding, and eating-disorder history need individualized guidance.
  • Short-term scale changes include water, glycogen, and digestion—not only tissue change.

Sources and next reading

The resting-energy equation comes from the original Mifflin–St Jeor study. A systematic review found it among the more reliable common equations while still documenting individual error.