Daily calorie calculator (BMR and TDEE)
Your daily calorie need (TDEE) is your basal metabolic rate multiplied by an activity factor. This calculator uses the Mifflin-St Jeor equation and compares it with the revised Harris-Benedict equation. A moderately active 30-year-old man at 176 lb and 5'11" burns about 2,760 calories a day. Subtract 500 to lose roughly 1 lb per week.
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Estimate only. These equations give a population average; your real needs can differ by about 10%. This tool is not a substitute for medical advice.
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The equations behind the calculator
Your basal metabolic rate (BMR) is the energy your body burns at complete rest. This tool uses the Mifflin-St Jeor equation (1990), which the Academy of Nutrition and Dietetics found to be the most accurate of the common formulas, and shows the revised Harris-Benedict equation (Roza and Shizgal, 1984) beside it. W = weight in kg, H = height in cm, A = age in years.
Mifflin-St Jeor, men: \( 10 \times W + 6.25 \times H - 5 \times A + 5 \) Mifflin-St Jeor, women: \( 10 \times W + 6.25 \times H - 5 \times A - 161 \) Harris-Benedict, men: 88.362 + 13.397 × W + 4.799 × H − 5.677 × A Harris-Benedict, women: 447.593 + 9.247 × W + 3.098 × H − 4.330 × A TDEE = BMR × activity factor
Activity factors and weight goals
| Activity level | Factor |
|---|---|
| Sedentary | 1.2 |
| Lightly active | 1.375 |
| Moderately active | 1.55 |
| Very active | 1.725 |
| Extra active | 1.9 |
A pound of body fat holds about 3,500 calories. Cutting 500 calories a day therefore adds up to 3,500 a week, or about 1 lb. A pace of 0.5 to 1 lb per week is realistic. Do not go below 1,200 calories (women) or 1,500 calories (men) without medical supervision.
How accurate is it?
These equations come from population averages. They know nothing about your muscle mass, genetics or thyroid. Weigh yourself weekly for three weeks while eating at your estimate: if your weight is stable, the estimate fits you; if not, adjust by 100 to 200 calories.
Needs also change during pregnancy, breastfeeding and illness. In those cases, talk to your doctor or a registered dietitian.
3 real-life examples
A 30-year-old man, 176 lb, 5'11", moderately active
At 80 kg and 180 cm: \( 800 + 1{,}125 - 150 + 5 = \) 1,780 calories BMR. × 1.55 = 2,759 calories a day to maintain. Harris-Benedict gives a BMR of 1,854, or about 2,873 a day.
A 35-year-old woman, 137 lb, 5'5", lightly active
At 62 kg and 165 cm: \( 620 + 1{,}031 - 175 - 161 = \) 1,315 calories BMR. × 1.375 = 1,808 calories a day. To lose slowly, aim for about 1,558 (−250).
A 28-year-old man, 180 lb, 5'10", moderately active
At 81.6 kg and 177.8 cm: \( 816 + 1{,}111 - 140 + 5 = \) 1,793 calories BMR. × 1.55 = 2,779 calories a day. Eating 2,279 (−500) means about 1 lb lost per week.