Calorie Calculator

Which equation does the tool use?

Mifflin–St Jeor: 10 × weight (kg) + 6.25 × height (cm) − 5 × age, then + 5 for the male setting or − 161 for the female setting. That gives the resting figure, which is multiplied by the activity factor to produce the maintenance value. These are the figures built into this tool.

What do the activity options multiply by?

The multipliers are 1.2, 1.375, 1.55, 1.725 and 1.9 for the five levels, applied to the resting figure. The tool does not add exercise on top, so choose one level and it covers everything. The resting figure itself is not displayed, only the maintenance value after the multiplier.

How are the protein, fat and carbohydrate grams worked out?

Protein is 1.8 g per kg of the weight you entered, rounded. Fat is 25% of the target calories divided by 9, rounded. Carbohydrate is what remains after protein at 4 kcal per gram and fat at 9, divided by 4. These proportions are fixed in the code and cannot be changed in the form.

Does the goal option predict a change in body weight?

No. The goal list only adds or subtracts 250, 500 or 750 kcal per day from the maintenance value. The tool does not model how the body responds and makes no statement about how much weight anyone will gain or lose.

Can the macro grams add up to more than the target?

Yes. Carbohydrate is floored at zero, so when protein and fat already exceed the target the other lines still print. For a 50 kg, 150 cm, 60-year-old on the female setting, sedentary and subtracting 750, the target is 422 kcal with 90 g protein and 12 g fat, which exceeds it, and carbohydrate shows 0 g. No minimum is applied to the target.

What if a box is empty or zero?

An emptied box is read as 0. If weight, height or age is 0 or below, the tool shows “Enter weight, height and age above 0” instead of numbers. Earlier a zero entry returned a few calories as if it were a real answer.

Which units and sex options are supported?

Kilograms, centimetres and years only, so convert pounds and inches first. The sex field has two settings, male and female, and there is no input for pregnancy, breastfeeding, body fat or age under 18. The female setting gives a resting figure 166 kcal lower than the male setting for the same height, weight and age.

Is this medical or dietary advice?

No. It evaluates one published equation and fixed ratios, and it does not know your health or history. A doctor or registered dietitian governs any decision about how much to eat.