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Calorie Calculator

Estimate maintenance calories with the Mifflin-St Jeor equation.

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Results

Result Enter values to calculate.
Your result explanation will appear here.

Useful next checks

  • Treat the result as general guidance, not a diagnosis.
  • Check unusual results with a qualified health professional.
  • Retest with accurate measurements for a better estimate.

Intro

Use this calorie calculator to estimate daily maintenance calories from age, sex, height, weight, and activity level. The result gives a starting estimate for how many calories may maintain current body weight.

What this calorie calculator does

The calculator estimates basal metabolic rate, then adjusts it for activity. Basal metabolic rate is the approximate energy your body uses at rest. Activity level increases the estimate to reflect daily movement and exercise.

Use it for questions such as:

  • What is my estimated maintenance calorie intake?
  • How much does activity level change the estimate?
  • What starting point should I use for weight planning?
  • How do height, weight, age, and sex affect the estimate?

How it works

This tool uses the Mifflin-St Jeor equation to estimate resting energy needs. It then multiplies that estimate by an activity factor, such as sedentary, lightly active, moderately active, or very active.

The result is an estimate of total daily energy expenditure. It is not a precise measurement of metabolism.

Example calculation

A moderately active adult will usually have a higher maintenance estimate than a sedentary adult with the same age, sex, height, and weight. If the inputs stay the same and only the activity level changes, the difference shows how much the activity multiplier affects the final result.

Try adjusting one field at a time. This makes it easier to see whether the result is mainly being moved by body size, age, or activity level.

How to use the result

Use the number as a starting point for planning, then compare it with real-world results over time. If body weight is stable for several weeks, actual intake may be close to maintenance. If weight changes, actual maintenance may be higher or lower than the estimate.

For body size context, use the BMI Calculator. For hydration planning, use the Water Intake Calculator.

Assumptions and limitations

  • The estimate depends heavily on accurate height, weight, age, and activity inputs.
  • Activity multipliers are broad categories, not exact measurements.
  • Sleep, training, stress, hormones, medication, illness, and metabolic adaptation can affect real needs.
  • Weight loss, weight gain, pregnancy, eating disorders, and medical conditions may require professional guidance.
  • This is general health information, not medical or nutrition advice.

FAQs

  • Is this my exact maintenance intake? No. It is a starting estimate that should be adjusted using real progress and wellbeing.
  • Which activity level should I choose? Pick the level that reflects your average week, not your most active day.
  • Can I use this for weight loss? It can provide a starting point, but aggressive calorie changes should be handled carefully.
  • Why do two calculators give different answers? Different equations, activity factors, and rounding choices can produce different estimates.

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Frequently asked questions

Which formula is used?

The calculator uses the Mifflin-St Jeor equation and multiplies by an activity factor.

Are calorie needs exact?

No. Real needs vary with body composition, habits, health, and tracking accuracy.