How to use this calculator
Choose Mifflin–St Jeor or revised Harris–Benedict (1984). Both use weight, height, age, and an equation coefficient. An activity multiplier gives an approximate maintenance intake. The multiplier is a rough scenario rather than measured daily expenditure.
- Enter age (years), equation coefficient, measurement system and review the remaining options.
- Select Calculate or change a value to update the result. Read the result label and units before copying.
- Use Reset to restore the worked starting values.
Formula and method
For adults only; not a diet prescription. Individual needs vary. Excludes pregnancy, lactation, and medical conditions.
Worked example
A 30-year-old male at 70 kg and 175 cm has a resting estimate of 1,648.75 kcal/day. With a sedentary activity factor of 1.2, estimated maintenance energy is 1,978.5 kcal/day.
Questions about calorie needs calculator
How many calories should I eat to lose weight?
There is no single calorie target that suits everyone. Estimate maintenance needs first, then discuss an appropriate eating and activity plan with a qualified health professional. Needs vary with age, body size, activity, health, and individual circumstances. Avoid treating a calculated deficit as a guaranteed weight-loss outcome.
How can I estimate my daily calorie needs?
Enter the requested body measurements, age, and activity level. This tool estimates resting energy needs using the selected equation and applies an activity multiplier to estimate maintenance calories. It is a starting estimate rather than a direct measurement of your metabolism.
What is the difference between BMR and total daily energy expenditure?
BMR describes energy needed for basic functions at rest under standardized conditions. Total daily energy expenditure also includes movement, exercise, and digesting food. Predictive resting-energy equations and activity multipliers approximate these quantities; the calculator does not measure either directly.
How does activity level affect calorie needs?
More daily movement generally increases energy expenditure. This tool multiplies estimated resting needs by the selected activity factor, so choosing a higher factor raises the maintenance estimate. Consider your usual routine across the week, including work and everyday movement, rather than only your hardest workout.
Why are calorie calculator results only estimates?
Equations describe population patterns and cannot capture every person’s body composition, health, medication effects, or changing routine. Activity categories are also approximate. Review the estimate with a professional when using it for health decisions. Adult weight-management estimates should not be applied to children or to pregnancy or breastfeeding without appropriate care.
Choose the tool for your question
- BMR: See the resting-energy estimate without an activity multiplier.
What assumptions should I check?
For adults only; not a diet prescription. Individual needs vary. Excludes pregnancy, lactation, and medical conditions.
Are my inputs saved?
Calculations run in your browser. We store only tool IDs for favorites and recent tools. Sharing inputs in links is disabled for this category.
Health tools provide general estimates, not diagnoses or personal medical advice. BMI offers a labeled CDC child/teen reference; adult screening bands must not be applied to children. Discuss health and exercise decisions with a qualified professional. Read the tool-specific sources below for background on the method.