How Your Daily Calorie Needs Are Calculated (TDEE Explained)

“How many calories should I eat?” is probably the most-asked nutrition question. The answer depends on your body and your lifestyle — and the math is surprisingly straightforward.

Two-step process

1. Calculate your BMR (Basal Metabolic Rate) — calories burned at complete rest
2. Multiply by an activity factor to get TDEE (Total Daily Energy Expenditure)

The Mifflin–St Jeor equation (most accurate for modern populations)

Male:   BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5
Female: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161

Activity multipliers

Level	Multiplier	Description
Sedentary	1.2	Desk job, no exercise
Lightly active	1.375	Light exercise 1–3 days/week
Moderately active	1.55	Moderate exercise 3–5 days/week
Very active	1.725	Hard exercise 6–7 days/week
Extremely active	1.9	Athlete or physical job + training

Worked example

Male, 28, 75 kg, 178 cm, moderately active:

BMR = 10(75) + 6.25(178) − 5(28) + 5 = 750 + 1112.5 − 140 + 5 = 1727
TDEE = 1727 × 1.55 = 2677 calories/day

That’s his maintenance — eating this many calories keeps weight stable.

Using TDEE for goals

• Lose weight: Eat 300–500 below TDEE (lose ~0.5kg/week)
• Gain weight: Eat 300–500 above TDEE
• Maintain: Eat at TDEE
• Never go below BMR — it harms metabolism and muscle

Why calculators are estimates, not prescriptions

These formulas use statistical averages. Your actual TDEE depends on genetics, muscle mass, fidgeting habits, sleep quality, stress levels, and more. Use the calculator as a starting point, then adjust based on real-world results over 2–3 weeks.

Use the OurDailyCalc calorie calculator for an instant TDEE estimate with goal-specific targets and macro split.

TL;DR

• TDEE = BMR × Activity Multiplier
• Mifflin–St Jeor is the most accurate modern BMR equation
• A 500 calorie deficit loses ~0.5kg/week
• Treat the number as a starting point and adjust based on results