Calorie Calculator
Calculate your daily calorie needs with our free, gender-specific TDEE and BMR calculator. Uses the evidence-based Mifflin‑St Jeor formula.
Last clinically reviewed: April 1, 2026. Next review: October 1, 2026.
Calorie Needs Calculator
How the Calculator Works
Our calculator uses the Mifflin‑St Jeor formula, the most accurate BMR equation for healthy adults. BMR (Basal Metabolic Rate) is the number of calories your body burns at rest. TDEE (Total Daily Energy Expenditure) is calculated by multiplying BMR by your activity level factor.
A safe and sustainable calorie deficit for weight loss is typically 500 kcal/day, leading to about 1 lb of weight loss per week. For weight gain, a 500 kcal/day surplus supports gradual muscle growth.
The Mifflin‑St Jeor formula is most accurate for healthy adults aged 18-80. Results may be less accurate for individuals with certain medical conditions, extreme body compositions, or those taking medications affecting metabolism.
For more detailed guidance, visit the CDC: How to Use Calories to Manage Weight (link may be temporarily unavailable in some regions) and Mayo Clinic: Calorie Counting for Weight Loss.
Pregnant or breastfeeding women • Individuals with metabolic disorders (diabetes, thyroid disease) • People with eating disorders or extremely low/high BMI • Those recovering from major illness or surgery.
Always consult a registered dietitian or physician before starting a calorie-restricted diet.
Frequently Asked Questions
How is BMR and TDEE calculated?
We use the Mifflin‑St Jeor formula, which is clinically validated for estimating resting energy expenditure. TDEE is BMR multiplied by your activity factor.
What calorie deficit is safe for weight loss?
A 500 kcal/day deficit is generally considered safe, resulting in approximately 1 lb of weight loss per week. Consult a healthcare provider before starting any diet.
Can athletes or bodybuilders use this calculator?
Yes, but results are estimates. Individuals with very high muscle mass may have higher calorie needs. Use the 'Very Active' or 'Extra Active' settings for best accuracy.
How often should I recalculate my calorie needs?
Recalculate every 2-4 weeks, especially after significant weight changes or shifts in your activity level.
Can I adjust the calorie surplus/deficit?
Yes. For advanced goals, you can adjust the surplus to 250-750 kcal/day for muscle gain, or use a smaller deficit for slower, more sustainable weight loss. Always consult a healthcare provider before making significant changes.
Last clinical review: April 1, 2026. Next review: October 1, 2026.