Calorie calculator
Daily calorie intake for losing, keeping or gaining weight.
The equation uses a different constant for men and women.
A factor of 1.375× on the basal metabolic rate.
Losing and gaining are both counted with a fifteen percent change.
Daily intake to keep the weight
1,997 kcal
8,355 kJ
Basal metabolic rate
1,452 kcal
What the body burns at complete rest.
Total daily energy use
1,997 kcal
The basal rate and movement together.
Difference from what you burn
0 kcal
The daily surplus or deficit.
Protein
125 g
Keeps muscle, fills you up the most.
Carbohydrates
225 g
The main fuel for movement.
Fat
67 g
Needed for hormones and vitamins.
The result is an estimate from the Mifflin–St Jeor equation. Real energy use differs between people by hundreds of kilocalories depending on genetics, muscle mass and health. This is not medical advice; in pregnancy, illness or an eating disorder follow your doctor. Nothing is uploaded, your browser does the maths.
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More about Calorie calculator
How the daily intake is worked out
First comes the basal metabolic rate from the Mifflin–St Jeor equation, the energy the body uses lying still. That figure is multiplied by an activity factor to give the total daily energy use, and the goal then moves the intake fifteen percent up or down.
Fifteen percent is deliberately modest. A steeper deficit costs muscle and is hard to hold; a steeper surplus mostly adds fat. If you enter a target weight, the tool also estimates how many weeks the change would take at this pace.
The macros split the intake into protein, carbohydrates and fat, with protein set higher when losing weight — it keeps muscle and is the most filling of the three.
Frequently asked questions
How accurate is the number?
It is an estimate. Between two people of the same height, weight and age the real energy use can differ by hundreds of kilocalories depending on muscle mass, genetics and health. Treat it as a starting point and adjust after two or three weeks by what the scales say.
Which activity level should I pick?
Count deliberate exercise, not being generally busy. Most people with a desk job and a couple of sessions a week fall under “light”. Over-stating activity is the most common reason the number comes out too high.
Why is the basal rate lower than the total?
The basal rate is what you would burn in bed all day. Everything else — walking, work, training, digestion — sits on top of it, which is what the activity factor covers.
Is this medical advice?
No. In pregnancy, illness or an eating disorder, follow your doctor instead. Nothing you enter is uploaded; the whole calculation runs in your browser.