CODDY Tool

TDEE Calculator

Find your maintenance calories and targets for losing or gaining.

Calculate resting energy with Mifflin–St Jeor, scale it by your activity level, and get calorie targets plus a macronutrient split in grams.

Everything you enter stays in this browser tab. Nothing is sent to our servers, logged or stored.

This is one of the thingsHealth Calculatordoes — open it for everything else it supports.

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What Health Calculator supports

  • BMIBody mass index and healthy range.
  • BMR & caloriesResting and daily energy.
  • Body fatUS Navy tape method.
  • Ideal weightFour formulas compared.

About TDEE Calculator

Total daily energy expenditure is what you burn in a day: your basal metabolic rate — the energy used keeping you alive at complete rest — multiplied by a factor for how much you move.

The BMR half is reasonably well established. Mifflin–St Jeor predicts measured resting energy within about 10% for most people, which is why it replaced the older Harris–Benedict equation in clinical practice. Both are shown here, because plenty of calculators still use the older one and produce a different number for the same person.

The activity multiplier is the weak link, and no calculator can fix it. The gap between sedentary and lightly active is roughly 175 calories a day for an average adult, and deciding which describes you is a judgement call. The practical approach is to pick one, eat to it consistently for two or three weeks, and adjust based on what actually happens — your own weight trend is a better estimate of maintenance than any equation.

How to use it

  1. Choose metric or imperial

    Switching converts what you have already entered rather than reinterpreting it.

  2. Enter your details

    Everything is calculated in your browser as you type. Nothing is sent anywhere.

  3. Read the result in context

    Each figure is shown with what the formula can and cannot tell you.

Frequently asked questions

What is the difference between BMR and TDEE?

BMR is what you would burn lying still all day — breathing, circulating blood, maintaining temperature. TDEE adds everything else: moving, digesting, exercising. TDEE is always the larger number and is the one to eat to.

How big should a calorie deficit be?

500 calories a day is the usual figure for around half a kilogram a week, based on roughly 7,700 calories per kilogram of fat. Larger deficits are harder to sustain and cost more muscle. The number matters far less than being able to keep it up.

Why is my TDEE different on other sites?

Different formulas and different activity multipliers, usually unstated. A Harris–Benedict BMR and a Mifflin–St Jeor one can differ by over a hundred calories, and activity factors vary between calculators. None is authoritative — they are all estimates.

What macro split should I use?

For most people it matters much less than total calories and getting enough protein. A balanced 30/40/30 split works well as a starting point. Protein is the one worth being deliberate about, particularly in a deficit, because it helps preserve muscle.

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TDEE Calculator is free to use with no account, no watermark and no usage limits. Last updated 14 August 2026.