// Basic Fitness Calculators

TDEE Calculator

Estimate your total daily energy expenditure — the calories you burn across a whole day, training included.

Your details

Your result

Your TDEE
2,633kcal/day
BMR
1,699kcal/day
Mild loss (−500)
2,133kcal/day
Lean gain
2,896–3,160kcal/day

Estimates are for general guidance only and are not medical advice. For a personalised plan, book a free guided tour at RPM Gym.

What your result means

Your TDEE is your BMR multiplied by an activity factor. BMR is what you would burn lying still for 24 hours; the multiplier is a bracket that stands in for everything else you do: training, walking, work, fidgeting.

The deficit and surplus figures shown aren't prescriptions. A 500 kcal deficit is a common starting point because it maps to roughly half a kilogram of fat per week, and the gain figure is a 10–20% band over expenditure rather than a fixed number, because no single surplus has been established as optimal. Both are starting estimates you adjust against real weight data.

How it is calculated

Mifflin-St Jeor BMR × activity multiplier

BMR = (10 × weight kg) + (6.25 × height cm) − (5 × age) + 5 for men, − 161 for women. TDEE = BMR × activity factor (1.2 sedentary, 1.375 light, 1.55 moderate, 1.725 active, 1.9 very active)

What it assumes

  • Mifflin-St Jeor was derived in adults and is the equation most commonly recommended for general use; it still carries meaningful individual error.
  • The activity multipliers are broad brackets, not measurements. Two people picking 'moderate' can genuinely differ by several hundred calories.
  • Body composition isn't an input. At the same height, weight and age, a lean person and a less lean person get the same estimate.

Units and rounding

  • Weight in kilograms, height in centimetres, age in years.
  • The activity factor is selected, not typed, so it can't fall outside the published range.
  • Missing or zero inputs return no result rather than a nonsense calorie figure.

Worked example

A 30-year-old man, 80 kg, 180 cm, training 3–5 days a week (moderate, 1.55).

  1. BMR = (10 × 80) + (6.25 × 180) − (5 × 30) + 5
  2. = 800 + 1125 − 150 + 5 = 1,780 kcal/day
  3. TDEE = 1,780 × 1.55 = 2,759 kcal/day
  4. Mild loss = 2,759 − 500 = 2,259 kcal/day
  5. Lean gain = 2,759 × 1.10 to 1.20 = 3,035–3,311 kcal/day

A TDEE of about 2,759 kcal/day, from a BMR of 1,780 kcal/day.

Limitations

  • Every TDEE equation is an estimate. Published comparisons put predictive equations within roughly ±10% for most people, which at 2,700 kcal is a spread of several hundred calories.
  • The activity multiplier is the largest source of error, and it is the input you choose yourself. When in doubt, pick the lower bracket and let real weight data correct it.
  • TDEE isn't static. It moves with training load, weight change, sleep and non-exercise movement, which is one reason weight loss slows before any 'plateau' needs explaining.
  • It doesn't account for medical conditions or medications that affect metabolism. If either applies to you, this number is a conversation-starter with a doctor or dietitian, not a plan.
  • Tracked food intake carries its own error. Two estimates stacked on each other drift quickly, so the scale over 2–3 weeks matters more than the arithmetic.

What to do next

  • Treat the number as a hypothesis. Eat at it for two to three weeks, weigh yourself under the same conditions, and adjust from what actually happened.
  • Set your protein target before you split the rest. It's the macro with the clearest evidence behind it for body composition, and the easiest to under-eat.
  • If you're cutting, take the deficit from the smaller end first. A larger deficit isn't a faster result if it costs you training quality and adherence.
  • If the weekly average isn't moving after three weeks, change one variable, usually intake, rather than recalculating your TDEE.

Sources

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// Frequently Asked

Questions, answered.

Can I raise my TDEE?

Yes, but not mainly through metabolism. The component that moves most is everyday movement: steps, standing, general restlessness, which can vary by hundreds of calories between two similar people. Added muscle raises it too, though by less than most expect: roughly 13 kcal per kilogram per day at rest.

Which activity level should I choose?

Count structured training honestly and be conservative about the rest. Three to five gym sessions a week with a desk job is 'moderate' (1.55), not 'active'. Most people over-select here, which is why the estimate reads high.

How accurate is a TDEE calculator?

It's a population equation applied to an individual, so expect roughly ±10% for most people and more if your body composition is unusual for your height and weight. Its value is as a starting point you then correct with two to three weeks of real weight data.

Should I eat my training calories back?

Not if you selected an activity multiplier that already includes your training. That would count the same sessions twice. Eat back tracked exercise calories only if you calculated from a sedentary baseline.

Why did my TDEE change when I lost weight?

A smaller body costs less to move and maintain, so BMR falls as weight falls. People also move less, often without noticing, when in a deficit. Recalculating every 4–5 kg of change keeps the estimate honest.

Is TDEE different for women?

The Mifflin-St Jeor equation applies a different constant by sex (−161 instead of +5), and women are on average smaller, so the resulting figure is typically lower. The method and the activity multipliers are the same.

Turn the estimate into a real target.

Estimates become programmes on the gym floor, not in a spreadsheet. Book a free guided tour at RPM Gym in Al Manhal.

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