Total Daily Energy Expenditure is the total calories your body burns in 24 hours — your BMR (basic survival energy) plus the calories burned digesting food, moving around, and exercising. Eating exactly your TDEE keeps weight constant; eating below it causes fat loss; eating above causes weight gain.

Which BMR formula does this use?

Mifflin-St Jeor, the most accurate equation for the general population per a 2005 American Dietetic Association review. Men: BMR = 10×kg + 6.25×cm − 5×age + 5. Women: BMR = 10×kg + 6.25×cm − 5×age − 161. TDEE = BMR × activity multiplier (1.2 sedentary to 1.9 very active).

How big a calorie deficit should I aim for?

A 15–20% deficit (300–600 kcal) is sustainable and preserves muscle. A 25%+ aggressive deficit accelerates fat loss but risks muscle loss, fatigue and hormonal disruption. As a rule, aim to lose no more than 0.5–1% of bodyweight per week.

What's the difference between BMR and TDEE?

BMR is your basal metabolic rate — calories your body burns at complete rest just to keep organs running, blood circulating and cells alive (about 60–75% of TDEE). TDEE adds the thermic effect of food (~10%) and all your activity (movement, exercise, fidgeting). Always plan calories around TDEE, never BMR.

Why does my TDEE seem low / high?

Mifflin-St Jeor estimates within ±10% for most people. Athletes with high muscle mass burn more than the formula predicts (try Katch-McArdle if you know your body fat %). Older adults, post-dieters or those with thyroid issues may burn 5–15% less than predicted. Use TDEE as a starting point; adjust ±100 kcal weekly based on actual scale trend.

🔥 TDEE Calculator

Calculate your Total Daily Energy Expenditure, BMR and calorie targets for cutting, maintaining or bulking. Mifflin-St Jeor formula.

Sex

Age

Units

Weight (kg)

Height (cm)

Activity Level

⚠️ Estimate only. Mifflin-St Jeor is accurate within ±10% for most adults. Athletes with high lean mass should use Katch-McArdle. Consult a registered dietitian / GP before pursuing aggressive deficits or surpluses, particularly if you have a medical condition.

Your Energy Budget Explained

Your body burns calories through four channels:

BMR (60–75%) — calories your organs use just to keep you alive at rest
NEAT (15–30%) — Non-Exercise Activity Thermogenesis: walking, fidgeting, posture
TEF (~10%) — Thermic Effect of Food (digestion). Protein has the highest TEF (20–30%)
EAT (5–15%) — Exercise Activity Thermogenesis: deliberate workouts

The sum is your TDEE. Eating exactly your TDEE holds weight stable. Eating below creates a deficit (fat loss); eating above creates a surplus (weight gain).

The Mifflin-St Jeor Formula

The 2005 American Dietetic Association review found Mifflin-St Jeor to be the most accurate BMR equation for the general population (more accurate than the older Harris-Benedict).

Men: BMR = 10×kg + 6.25×cm − 5×age + 5
Women: BMR = 10×kg + 6.25×cm − 5×age − 161

TDEE = BMR × activity multiplier (1.2 sedentary → 1.9 athlete).

Picking the Right Activity Multiplier

Most people overestimate their activity level. If your job is desk-based and you train 3 hours/week, you're "lightly active" (1.375), not "very active". A common rule: pick one tier lower than you initially think.

Setting a Cut or Bulk Target

Aggressive cut (−25%): fastest fat loss but risks muscle loss; max 8–12 weeks
Moderate cut (−15%): sustainable, preserves muscle; ideal for most people
Lean bulk (+10%): ~0.25 kg/week gain — minimises fat gain alongside muscle
Aggressive bulk (+20%): for hard-gainers or off-season; expect some fat gain

Adjust based on actual scale trend over 2–3 weeks. If you're not losing 0.5–1% of bodyweight per week on a cut, drop calories by another 100–200 kcal.

What to Do With Your TDEE

Pair it with our Protein Intake Calculator and Macro Calculator to translate calories into a daily protein, carb and fat split. Track for 2–3 weeks and adjust based on the scale trend, not day-to-day fluctuations.

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Important Note: This is an estimate, not a prescription. People with thyroid disorders, PCOS, recent significant weight loss, or eating disorder history should consult a registered dietitian before setting calorie targets. Pregnancy and breastfeeding require higher intakes — see a GP / midwife.

Related Calculators

Daily Calorie Calculator — TDEE based on age, weight, height and activity level.
Calorie Deficit Calculator — Daily calorie target to reach a goal weight. BMR + TDEE, weeks-to-goal projection and macro split.
Macro Calculator — Daily protein, carbs and fat split with cut/maintain/bulk presets and four split styles.