What this tool does
TDEE (total daily energy expenditure) is an estimate of calories that would hold your current weight if intake and activity stay similar. This calculator applies Mifflin-St Jeor (1990) for resting burn, multiplies by a standard activity factor, and labels the maintenance number. Fat-loss and lean-surplus bands sit beside it so you can see the neighborhood without opening three tools.
How it works
Enter sex, age, height, weight, and activity (metric or imperial). The tool converts to kilograms and centimeters, computes BMR with Mifflin-St Jeor, multiplies by your activity factor, and prints TDEE on the results card. Optional daily steps add a desk-day-plus-walking comparison next to the multiplier-based number. Harris-Benedict is not used for the headline TDEE here.
Formula and methodology
Step 1 — Mifflin-St Jeor BMR (1990): men 10×kg + 6.25×cm − 5×age + 5; women 10×kg + 6.25×cm − 5×age − 161. Step 2 — TDEE = BMR × activity factor: sedentary 1.2 (desk, little exercise), lightly active 1.375 (light training 1–3 days/week), moderate 1.55 (training ~3–5 days/week), active 1.725 (hard training most days), very active 1.9 (physical job or two-a-days). These multipliers are population averages — they do not capture fidgeting, a brutal commute, or NEAT shifts in a deficit.
How to interpret the result
If two weeks of eating near this number and a stable weekly weight average agree, you have a working maintenance. If weight drops, the estimate was high or intake was under-logged. If weight climbs, the reverse. Adjust 100–200 kcal or re-check the activity factor before you cut or add a large slice.
Example
An 80 kg, 180 cm, 30-year-old man: BMR = (10×80) + (6.25×180) − (5×30) + 5 = 800 + 1,125 − 150 + 5 = 1,780 kcal. At moderate (×1.55): TDEE ≈ 2,760 kcal. Sedentary (×1.2) would be ~2,140 kcal; active (×1.725) ~3,070 kcal. A 65 kg, 165 cm, 30-year-old woman at moderate: BMR ≈ 1,370 kcal → TDEE ≈ 2,120 kcal. One wrong activity rung moves the number 300–400 kcal — larger than many diet tweaks.
Common mistakes
- Picking “very active” because you trained twice while sitting the rest of the week.
- Stacking a physical-job multiplier and a separate “gym days” boost — the factor already includes your normal week.
- Treating TDEE as exact instead of a starting point that needs a two-week weight check.
- Copying a partner’s TDEE because you train together — size and NEAT differ.
- Recalculating from one restaurant weekend instead of a weekly average.
When this estimate may be off
- Body weight or height is a guess, or the activity dropdown does not match a normal week.
- You recently lost a lot of weight and expenditure has adapted downward.
- Injury, illness, or a desk week replaced the activity you typed.
- You are still growing, pregnant, or in a clinical metabolic setting this equation was not built for.
- You need measured RMR from indirect calorimetry — this page estimates only.