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TDEE Calculator – Mifflin-St Jeor Formula

Quick answer

This calculator computes your Total Daily Energy Expenditure with the Mifflin-St Jeor equation and activity multipliers from 1.2 to 1.9.

Figures are estimates from this calculator’s standard formula — adjust the inputs in the tool below for your exact number.

How the TDEE Calculator Works

TDEE = (10 × kg + 6.25 × cm − 5 × age + s) × activity multiplier, where s = +5 men / −161 women

Your Total Daily Energy Expenditure is the number of calories you burn each day combining your basal metabolic rate with all physical activity. This calculator first computes your BMR with the Mifflin-St Jeor equation, which the Academy of Nutrition and Dietetics considers the most accurate predictive formula for healthy adults. It then multiplies that value by an activity factor ranging from 1.2 for sedentary office work up to 1.9 for physical jobs plus hard daily training. Worked example: a 30-year-old, 80 kg, 178 cm man has a BMR of 10×80 + 6.25×178 − 5×30 + 5 = 1,783 kcal; with moderate activity (1.55) his TDEE is about 2,763 kcal per day.

  1. 1

    Enter your stats

    Provide weight, height, age and sex for the Mifflin-St Jeor BMR

  2. 2

    Pick activity level

    Choose from sedentary (1.2) to very active (1.9) based on your week

  3. 3

    Read your TDEE

    BMR is multiplied by the factor to give daily maintenance calories

Use Cases

Setting a weight-loss target

Eat 300–750 kcal below TDEE to lose 0.3–0.7 kg per week

Lean muscle gain

Add a 200–300 kcal surplus on top of TDEE to minimise fat gain

Maintenance phase

Match intake to TDEE to hold your current weight after dieting

Tips

  • 1

    Recalculate TDEE after every 4–5 kg weight change

  • 2

    Choose the lower multiplier when in doubt — most people overestimate activity

  • 3

    Track actual intake for two weeks and compare with scale trend to fine-tune

Common Mistakes

  • Selecting "very active" when training only 3 days a week

  • Ignoring calories from oils, sauces and drinks

  • Forgetting that TDEE falls as you lose weight

  • Copying someone else’s calorie target instead of computing your own

FAQs

What is a good TDEE formula multiplier for lifting 3–4 times a week?

Use 1.55 (moderate). With a 2,000 kcal BMR that gives a TDEE of 3,100 kcal.

How accurate is Mifflin-St Jeor for TDEE?

It predicts measured energy expenditure within about 10%, so a 2,600 kcal result may truly be 2,340–2,860 kcal.

How many calories below TDEE should I eat to lose weight?

A deficit of 500 kcal daily yields roughly 0.5 kg per week, because 1 kg of fat stores about 7,700 kcal.

Does TDEE change as I age?

Yes — BMR drops about 1–2% per decade after 30, so the same stats at 50 give a 50–100 kcal lower TDEE.

Is TDEE the same as maintenance calories?

Yes, TDEE is your maintenance intake: eat at it and your weight stays stable.

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