Free nutrition calculators

Five tools, five different numbers. All of them run in your browser: no sign-up, no account, and nothing you type reaches a server. Each page names the formula it uses and cites its source, because seeing where a number came from matters as much as the number.

• Calorie and macro calculatorYour daily calorie requirement (TDEE). Mifflin-St Jeor, four activity multipliers, and a ±500 kcal goal adjustment.
• BMR calculatorBasal metabolic rate: what you burn lying completely still. Also shows what it becomes at each of four activity levels.
• Macro calculatorSplits a calorie figure into grams of carbohydrate, protein and fat. Four presets plus your own ratio.
• Protein calculatorProtein need per kilogram of bodyweight, given as a range by goal. Not a single number, because the literature does not agree on one.
• BMI calculatorBody mass index, the WHO band, and the healthy weight range for your height.

Which tool answers which question

These five numbers are connected and usually needed in order. Your basal metabolic rate is what you burn doing nothing at all. Multiplied by an activity factor it becomes your daily calorie requirement. Dividing those calories into carbohydrate, protein and fat gives your macro split. Working protein out separately per kilogram of bodyweight shows whether that split actually meets your goal. BMI stands apart from all of it: it screens a height-to-weight ratio and plays no part in the energy calculation.

What these tools do not do

None of them diagnoses anything, and none measures your individual metabolism. All of them use population-level equations: they return the average for people of the same height, weight, age and sex. Your real expenditure can sit ten per cent or more away from that estimate. That is not a flaw, it is the limit of the method - and it is why Cookrange does not treat a target as fixed, but regenerates it alongside the real data you log.

Beyond the number: the mechanism pages

These tools give you a number. How that number becomes a plan, and with what limits, is covered separately:allergen filtering (the filter runs before the plan is shown),barcode food data (it comes from Open Food Facts),how AI meal planning works(which step of the plan this arithmetic is),photo calorie estimation (the estimate's confidence score) andis AI meal planning safe (who should not use these tools).