About this tool
Basal metabolic rate (BMR) is the energy your body burns at rest. This calculator uses the Mifflin-St Jeor equation: 10 x weight in kg + 6.25 x height in cm - 5 x age, then +5 for men or -161 for women. Your maintenance calories are the BMR multiplied by an activity factor from 1.2 for a desk job to 1.9 for athletes or heavy labor. For example, a 30-year-old woman who is 165 cm and 60 kg has a BMR of about 1,320 kcal, and with light exercise (x1.375) about 1,815 kcal a day. For gentle weight loss the tool shows maintenance minus about 300 kcal, but it never shows a figure under 1,200 kcal because eating that little is not recommended without medical supervision. The result is an estimate; real needs differ with muscle mass, genetics and health. It is for healthy adults aged 18 and over, and is not suitable for children, pregnancy or medical conditions. For reference only; it does not replace a doctor or dietitian. Nothing you enter is sent anywhere.
How to use
- Choose your sex and enter age, height and weight.
- Pick the activity level that matches a normal week.
- Read your BMR and daily maintenance calories.
- Use the numbers as a rough guide, not a strict rule.