Calorie and macro calculator
What you burn in a day and how to split it, with the equation that gets it least wrong outside a lab.
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This is worked out here, in your browser. Nothing you type — weight, height, anything — leaves your phone: this page sends no data anywhere.
How it is worked out
First resting metabolism with Mifflin-St Jeor, the most accurate of the desk-based equations: men, 10 × weight + 6.25 × height − 5 × age + 5; women, the same but − 161. That is multiplied by your activity factor to get total expenditure. The goal applies −20% or +10%, the rates that lose fat without losing muscle and gain muscle without gaining only fat. Macros: 1.8 g of protein per kilo (2.2 in a deficit), 25% of calories from fat and the rest from carbohydrate.
What it does not tell you
It is an estimate, and the normal error is 10% either way: two people identical on the scale can burn 300 kcal differently. The number that counts is the one the scale confirms in two weeks. And if your weight is not moving, what needs adjusting is the food, not the formula.
Where it comes from
Mifflin, St Jeor et al. (1990)
“A new predictive equation for resting energy expenditure”, Am J Clin Nutr.
Frankenfield et al. (2005)
Comparison of resting expenditure equations: Mifflin-St Jeor wins.
Morton et al. (2018)
Meta-analysis of protein and strength: the useful ceiling is around 1.6 g/kg.
To read slowly
Free on Get NovastraThis is general training information, not medical or personalised nutrition advice. If you have a health condition, are pregnant or take medication, the person who decides is your doctor.