Free Online TDEE Calculator

1. Enter weight, height, age and biological sex.
2. Pick the activity tier that honestly matches your week.
3. Read your TDEE in kcal/day — that's your maintenance calorie target.
4. Recalculate every few months as weight or activity changes.

BMR alone is what you'd burn lying in bed. TDEE — Total Daily Energy Expenditure — layers in the calories you spend on everything from walking to your desk to deliberate exercise. It's the figure you eat against to maintain weight; below it to lose; above it to gain.

The convention is to multiply BMR by a single factor that captures your week's activity: 1.2 sedentary (desk job, no exercise), 1.375 light (light exercise 1–3 days), 1.55 moderate (moderate exercise 3–5 days), 1.725 heavy (heavy exercise 6–7 days), 1.9 very heavy (twice-daily training or physical labour). The biggest source of error here is honesty — most people overestimate by one tier. If you do a 30-minute walk most days but otherwise sit at a desk, you're "light," not "moderate."

This tool uses Mifflin-St Jeor for BMR and the standard activity factors for TDEE. It's a starting estimate, not a guarantee — informational use only, not medical advice. Calibrate by tracking actual intake and weight changes for two weeks.