Calorie Calculator

By the FastFreeTools Editorial Team · Last reviewed: May 2026 · See our Editorial Policy for methodology, sourcing, and disclaimers.

Calculate daily calorie needs based on age, weight, height, and activity level. Methodology: uses the Mifflin-St Jeor equation (Mifflin et al., 1990), the formula recommended by the Academy of Nutrition and Dietetics for resting energy expenditure in adults. The result is multiplied by an activity factor (1.2 sedentary to 1.9 athlete) to estimate total daily expenditure. Educational tool only — see our editorial policy for the medical disclaimer.

About this tool

Understanding daily calorie needs is fundamental to nutrition management. Our Calorie Calculator uses the Mifflin-St Jeor equation — considered the most accurate estimation formula — to calculate Basal Metabolic Rate (BMR) based on age, gender, weight, and height, then multiplies by activity level for Total Daily Energy Expenditure (TDEE).

How to use Calorie Calculator

Select gender and enter age.
Enter weight (kg) and height (cm).
Choose activity level.
Click Calculate.

Tips & best practices

Mifflin-St Jeor is most accurate for ages 19-78.
-500 kcal/day ≈ 1 lb/week loss.
Be honest about activity level.
Recalculate as weight changes.

Common use cases

Setting calorie targets for weight management.
Planning meal prep.
Understanding athletic energy needs.
Comparing calorie needs by activity.

Privacy

This tool runs entirely in your browser. We do not upload, store, log, or process your input on any server. Open your browser's DevTools Network tab to verify — there is no outbound request with your data. See our Privacy Policy for details.

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