Calorie Calculator
Daily calorie needs
Nuclear Caloric Architecture
About the Calorie Calculator
Find out how many calories you need each day to maintain, lose or gain weight. The calculator estimates your resting energy use, applies your activity level and shows a suggested split of protein, carbohydrates and fat.
How to use the Calorie Calculator
- Select Male or Female and enter your Age, Weight (kg) and Height (cm).
- Choose your Physical Activity Multiplier, from the resting baseline up to a professional athlete or physical labourer.
- Press the calculate button to see your maintenance calories and the suggested targets for different goals.
Formula and method
Maintenance calories = BMR × activity multiplier. The multipliers used are 1.2 (little or no exercise), 1.375 (light, 1 to 2 days a week), 1.55 (moderate, 3 to 5 days), 1.725 (very active, 6 to 7 days) and 1.9 (athlete or heavy physical work).
A common rule of thumb is that 1 kg of body fat is roughly 7,700 kcal, so a daily deficit of about 500 kcal leads to around 0.5 kg of fat loss per week.
Worked example
If your BMR is 1,780 kcal and you exercise three to five days a week (multiplier 1.55), your maintenance is about 1,780 × 1.55 = 2,759 kcal. Eating around 2,250 kcal would be a moderate deficit for weight loss.
Tips
- Be honest about your activity level. Most people overestimate it.
- Re-check your calories after every 5 kg of weight change, because your needs shift as your weight does.
- Weigh yourself a few times a week and compare the average across two to three weeks before changing your plan.
- Aim for changes that feel sustainable. Very aggressive deficits are hard to maintain.