Crunch Calorie Calculator
Your maintenance calories, targets for losing or gaining at the pace you pick, and the macro split to go with them — more goal rates and diet styles than the standard calculators offer.
How it works
Your resting burn (BMR) comes from the Mifflin-St Jeor equation — men: 10×kg + 6.25×cm − 5×age + 5; women: the same minus 161. Multiplying by your activity factor gives TDEE, the calories that hold your weight steady. A pound of body fat stores roughly 3,500 kcal, so a steady 500 kcal/day deficit or surplus moves weight by about a pound a week (the goal menu uses that math, with safety floors of 1,500 kcal for men and 1,200 for women). Macros convert at 4 kcal per gram of protein or carbs and 9 per gram of fat.
Frequently asked questions
How many calories do I need to maintain my weight?
That is your TDEE: BMR multiplied by activity (1.2 sedentary up to 1.9 athlete). For a moderately active 30-year-old man at 80 kg and 180 cm it is about 2,760 kcal a day — the calculator shows yours with every activity level for comparison.
How big a deficit is safe for weight loss?
A 250–500 kcal daily deficit (roughly 0.25–0.5 kg a week) is the range most guidelines consider sustainable. The fast −1,000 option is aggressive, and this calculator floors targets at 1,500 kcal (men) and 1,200 kcal (women) — eating below that belongs under medical supervision.
Why do macros matter if calories are equal?
Calories drive weight change, but the split drives how you feel getting there: protein protects muscle and satiety, carbs fuel training, fats cover hormones and absorption. The four styles let you match the split to how you actually eat.
Is Mifflin-St Jeor the best formula?
For most adults it is the most accurate of the common equations in validation studies, which is why dietitians default to it. If you know your body-fat percentage, the BMR Calculator's Katch-McArdle option can be closer for very lean or very heavy builds.
⚡ Want BMR three different ways?
The BMR Calculator compares Mifflin-St Jeor, Harris-Benedict and Katch-McArdle side by side.