Calorie Calculator
Health
Daily calorie needs calculator
Enter your age, sex, height, weight, and activity level to estimate how many calories you need each day.
Calorie Calculator
Estimated BMR
1,649 kcal/day
Estimated daily calories
2,556 kcal/day
Activity multiplier
1.55
How calculations work
This calculator estimates daily calorie needs using the Mifflin–St Jeor equation for basal metabolic rate (BMR), then multiplies BMR by an activity factor to produce a daily-calorie estimate. Inputs are weight, height, age, sex, and a standard activity multiplier. All math runs locally in your browser; no external services are used.
How to interpret results
The displayed values are estimates only. The BMR value reflects resting energy needs, while the estimated daily calories include routine activity based on the selected multiplier. Use these numbers as general references for planning meals or budgets—not as medical or dietary advice.
Disclaimer
What this calculator does
This calculator estimates your Total Daily Energy Expenditure (TDEE) — the approximate number of calories your body burns in a day including physical activity. It first computes your Basal Metabolic Rate (BMR) using the Mifflin–St Jeor equation, then multiplies by an activity factor to account for your exercise level. The result is a personalised calorie target for weight maintenance.
Who should use this calculator
Anyone planning a diet, setting fitness goals, or curious about their energy needs — including people starting weight-loss programmes, athletes estimating fuel requirements, and nutrition enthusiasts wanting a quick baseline. While useful for planning, this calculator does not replace a personalised assessment by a registered dietitian or healthcare provider.
How this calculator works
The Mifflin–St Jeor formula first computes your BMR from age, sex, height (cm), and weight (kg). The BMR represents calories burned at complete rest. This value is then multiplied by an activity factor: sedentary (×1.2), lightly active (×1.375), moderately active (×1.55), very active (×1.725), or extra active (×1.9). The product is your estimated TDEE. All calculations run client-side in your browser — no data leaves your device.
How to interpret your result
The TDEE figure represents the estimated daily calories needed to maintain your current weight at the selected activity level. To lose weight, consume fewer calories than your TDEE (a deficit of 10–20% is commonly recommended). To gain weight or build muscle, consume slightly more. Adjust the activity level selector to see how exercise intensity changes your calorie needs.
Example
A 30-year-old woman weighing 65 kg, 165 cm tall, and moderately active might see a BMR of approximately 1,387 kcal/day and a TDEE of about 2,150 kcal/day. A 40-year-old man weighing 80 kg, 178 cm tall, and lightly active might see a BMR of 1,727 kcal/day and a TDEE of roughly 2,375 kcal/day. Enter your own values above for a personalised estimate.
Limitations & disclaimer
Results are estimates based on a mathematical formula and do not replace medical, nutritional, or metabolic testing. Body composition, genetics, hormonal status, and health conditions all influence actual energy needs. The Mifflin–St Jeor equation tends to be more accurate than the older Harris–Benedict formula for most adults, but individual variation remains significant. Consult a registered dietitian for individualised nutrition advice.
Frequently asked questions
What is the Mifflin–St Jeor equation?
It is one of the most widely cited formulas for estimating Basal Metabolic Rate (BMR). For men: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161 + 166. For women the constant is −161 instead of +5. The result is multiplied by an activity factor to estimate total daily energy expenditure (TDEE).
What activity level should I choose?
Sedentary (×1.2) means little or no exercise. Lightly active (×1.375) is light exercise 1–3 days/week. Moderately active (×1.55) is moderate exercise 3–5 days/week. Very active (×1.725) is hard exercise 6–7 days/week. Choose the level that best matches your average week.
How do I use TDEE for weight loss?
A common approach is to eat 10–20% fewer calories than your TDEE. A 500 kcal/day deficit typically corresponds to roughly 0.5 kg (1 lb) of weight loss per week. Extreme deficits are not recommended — consult a nutrition professional.
Why does my result differ from other calculators?
Different calculators use different BMR formulas (Harris–Benedict, Katch–McArdle, etc.) and activity multipliers. Small differences are normal. If precision matters, consider indirect calorimetry testing through a healthcare provider.
Is this calculator suitable for building muscle?
Yes, as a starting point. To build muscle, most people need a modest caloric surplus (5–15% above TDEE) combined with resistance training and adequate protein intake. A sports nutritionist can tailor a plan to your goals.