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Calorie Calculator

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Free tool

Calorie Calculator

Estimate BMR and daily maintenance calories from age, sex used in the equation, height, weight, and activity level. Use the result as a starting estimate, not a prescription.

Privacy note: This tool is marked browser-side in the tool registry. It works with generated values or pasted input rather than a required local file upload. No account is required for this public tool. Review data handling.
Calorie inputs
Estimate BMR with Mifflin-St Jeor, then multiply by activity level for TDEE.

Try a sample calorie profile

Calorie equations are estimates. They do not measure metabolism, medical conditions, medication effects, pregnancy, or individual training adaptation.
Estimated calories
BMR and daily maintenance estimate.

Maintenance estimate

1,914 kcal/day

BMR estimate

1,392 kcal/day

Activity factor

1.375x

Mild loss

1,664 kcal/day

Faster loss

1,414 kcal/day

Mild gain

2,164 kcal/day

Faster gain

2,414 kcal/day

Avoid aggressive calorie targets without professional guidance. Needs vary and may require clinical support.
Activity levels
Activity multipliers are simple estimates and can overstate or understate real needs.

Sedentary

Little exercise

1.2x

Light

Exercise 1-3 days/week

1.375x

Moderate

Exercise 3-5 days/week

1.55x

Very active

Hard exercise 6-7 days/week

1.725x

Extra active

Physical job or intense training

1.9x

Quick answer

A calorie calculator estimates BMR first, then multiplies by activity level to estimate maintenance calories.

The result is a planning estimate, not medical, nutrition, or weight-loss advice.

Best inputs for calorie estimates

Use current measurements

Height, weight, age, and activity level should reflect your current situation.

Treat activity as an estimate

Activity multipliers are broad averages and can miss training load, job demands, and daily movement.

Mifflin-St Jeor model

BMR = 10w + 6.25h - 5a + s

Weight is kilograms, height is centimeters, age is years, and s is +5 for male and -161 for female in the equation.

Estimate limits

TDEE estimates can be off because activity, muscle mass, health status, medications, and tracking accuracy vary. Adjust based on real-world results and professional guidance.

Calculations are handled in the browser for this tool based on the current public implementation. Avoid entering sensitive health details unless you have reviewed the implementation.

Example, assumptions, and limitations
Calorie estimates are starting points that need real-world adjustment.

Example

Enter age, height, weight, sex used in the equation, and activity level to estimate BMR and maintenance calories.

Assumption

The page uses Mifflin-St Jeor plus activity multipliers, which are predictive formulas rather than measured metabolism.

Limitation

Training load, illness, medication, body composition, and tracking accuracy can make real calorie needs higher or lower.

Common use cases
Use calorie estimates as a baseline for planning, then adjust with real-world feedback.

Maintenance planning

Estimate a starting daily calorie target for maintaining current weight.

BMR comparison

Compare estimated resting energy needs before activity multipliers are applied.

Activity scenarios

See how sedentary, moderate, and active multipliers change TDEE estimates.

Nutrition notes

Create a baseline estimate before discussing a plan with a qualified professional.

Common mistakes to avoid
These checks help prevent bad outputs, failed exports, and confusing results.

Treating TDEE as a measured value

The result is a formula estimate. Real maintenance calories can differ because activity, body composition, and tracking accuracy vary.

Choosing an activity level too high

Activity multipliers are broad averages. If in doubt, compare nearby levels instead of assuming one number is exact.

Making aggressive diet changes from one estimate

Use the result as a planning baseline and seek qualified guidance for medical, nutrition, or weight-loss decisions.

Frequently asked questions

What is maintenance calories?

Maintenance calories are an estimate of how many calories you need per day to maintain current weight at your current activity level.

Why does sex matter in the equation?

The Mifflin-St Jeor equation includes a sex-specific constant. It is a predictive equation, not a measurement of an individual's metabolism.

Should I use the weight-loss numbers exactly?

No. They are simple estimates around maintenance calories. Large calorie changes should be discussed with a qualified professional.

Can athletes use this calculator?

Athletes may need more individualized estimates because training load and body composition can differ from the assumptions in general equations.

Suggested workflow

Daily health planning path

Move from calorie estimates to BMI context and sleep timing without treating any result as medical advice.