TDEE Calculator

What TDEE means

Total daily energy expenditure is everything you burn in a day added together. Your resting energy is the largest part of it for most people. On top of that sits the energy cost of moving around, of your job, of training, and of digesting what you eat.

TDEE is the number your goal is set against. Eat under it and you lose weight over time. Eat over it and you gain. It is the reference point, which is why it is worth understanding how the estimate is built rather than treating it as a fact about your body.

How the activity multiplier is chosen

Your TDEE here is your resting energy multiplied by an activity factor between 1.2 and 1.9. Rather than asking you to pick a label like "moderately active", which people read very differently, the multiplier is derived from two things you can answer accurately.

Your total weekly sessions, resistance and cardio combined, set the starting tier. Your work day then moves it: mostly seated leaves it where it is, being on your feet moves it up, and physical work moves it up further. A physical job also sets a floor, so a labourer who does not train is not treated as sedentary.

• 1.2: sedentary, desk work, no training.
• 1.375 to 1.55: a few sessions a week, or a job that keeps you moving.
• 1.725 to 1.9: frequent training, or physical work combined with training.

How accurate is a TDEE estimate

Less accurate than the decimal places suggest. Every equation of this kind was fitted to population data, so it describes an average person with your height, weight, age and sex rather than you specifically. Two people with identical inputs can genuinely differ by several hundred calories.

Treat the figure as a starting hypothesis. Eat at it for a few weeks, watch the trend on the scale, and correct from what happened. Real data about you beats any equation about people like you.

How these numbers are produced

Every figure on the results page comes from a fixed calculation, not from an AI guess. The same answers always produce the same numbers, which is why you can come back next month, enter the same details, and get the same targets.

An AI model writes the explanation you read underneath the numbers. It is given the figures after they have been calculated and it is not allowed to change them, recalculate them, or quote a figure the calculation did not produce.

• Resting energy is estimated with the Mifflin-St Jeor equation, or the Katch-McArdle equation if you tell us your body fat percentage, which is the more accurate of the two when that figure is known.
• Your activity multiplier comes from your weekly training sessions and how physical your work day is. The scale runs from 1.2 for sedentary to 1.9 for very high activity.
• We deliberately lean conservative on activity. Overestimating maintenance is the most common failure in consumer calculators, and it quietly makes every goal harder.

The limits built into this calculator

A calorie target handed to a stranger needs guardrails, so several are built in and cannot be overridden.

• Fat loss is capped at 1% of your bodyweight per week. Faster than that is not a setting you can choose here.
• Your calorie target never drops below the higher of your estimated resting energy and an absolute floor of 1500 calories for men or 1200 for women.
• There are no goal weight projections and no "you will reach X by this date" timelines, because those numbers are not knowable and they set people up to feel they have failed.
• If your details fall outside what a general calculator should answer, it stops and points you to a doctor or an Accredited Practising Dietitian instead of producing a number anyway.

What this calculator is not

This is general information. It is not personalised dietary advice and it is not medical advice. It cannot see your blood work, your training history, your medication or your relationship with food.

If you are managing a health condition, if you are pregnant or breastfeeding, if you have a history of disordered eating, or if you simply want targets built around your actual situation, speak to a doctor or an Accredited Practising Dietitian. That is a better use of your time than any calculator.