A 30-year-old man, 80 kg and 180 cm, burns about 1,780 kcal a day at rest. With a sedentary lifestyle that becomes 2,136 kcal a day.
Step 1: resting energy
The Mifflin-St Jeor equation estimates calories burned at rest: 10 × weight (kg) + 6.25 × height (cm) − 5 × age (years), then + 5 for men or − 161 for women.
For the example that is 800 + 1,125 − 150 + 5 = 1,780 kcal.
Step 2: activity
Multiply resting energy by a factor for daily activity: 1.2 sedentary, 1.375 lightly active, 1.55 moderately active, 1.725 very active. At 1.55 the example needs 2,759 kcal.
Use it as a starting point
The result is a population average. Track your weight over two or three weeks at that intake and adjust by small steps. Do not use it to set very low intakes without medical advice.
| Factor | kcal a day |
|---|---|
| 1.2 | 2,136 |
| 1.375 | 2,448 |
| 1.55 | 2,759 |
| 1.725 | 3,071 |
FAQ
Which formula does so67 use by default?+
Mifflin-St Jeor. You can switch formulas in the calorie calculator.
How accurate is the estimate?+
It is an average for people of similar size and age. Individual needs can differ by several hundred calories.