TDEE Calculator

BMR (basal metabolic rate) is the largest component — typically 60–75% of total burn. It's the energy your body uses just to keep you alive at complete rest. NEAT (non-exercise activity thermogenesis) covers the calories burned in normal daily movement: walking, fidgeting, standing, gestures. NEAT varies enormously between people — sometimes 800+ calories per day between a sedentary office worker and an active retail worker.

TEF (thermic effect of food) is the energy used to digest meals — about 10% of total intake on average, higher for protein (~20–30% of protein calories) and lower for fat (~0–3%). EAT (exercise activity thermogenesis) is the calories burned in formal workouts. For most people, EAT is the smallest component (often 5–15% of TDEE) and the most overestimated — a typical 30-minute jog burns 250–350 calories, easily replaced by one extra snack.

TDEE calculators apply an activity multiplier to BMR, typically: 1.2 (sedentary, desk job, no exercise), 1.375 (lightly active, light exercise 1–3×/week), 1.55 (moderately active, moderate exercise 3–5×/week), 1.725 (very active, hard exercise 6–7×/week), 1.9 (extremely active, hard daily exercise plus physical job).

These multipliers are rough averages and miss substantial NEAT variation. A construction worker who exercises lightly may have a higher TDEE than an office worker who exercises hard, because the construction worker is moving 8 hours a day. Pick the multiplier that best matches your typical day, not just your formal exercise schedule, then adjust based on actual weight trends.

Fitness trackers, smartwatches, and connected exercise equipment estimate TDEE based on heart rate, motion, and demographic inputs. Studies have found these devices typically overestimate energy expenditure by 10–30%, with the largest errors during light activity and varied movement.

If your tracker says you burned 3,000 calories and you ate 3,000 calories but gained weight, the tracker is the most likely culprit. Use device data as a relative measure (today vs. yesterday) rather than an absolute one, and calibrate your maintenance intake against actual weight trends rather than the device's TDEE estimate.

For weight loss, a 300–500 calorie/day deficit produces sustainable loss of 0.5–1 lb/week. Larger deficits work in the short term but lose more muscle, are harder to maintain, and can suppress BMR more aggressively. The slowest sustainable diet usually produces the best long-term outcome.

For weight gain (intentional, e.g., for athletic development), 250–500 calorie/day surpluses typically produce 0.5–1 lb/week of gain. Gaining more aggressively tends to add more fat than muscle. Both directions of weight change become harder over weeks because TDEE itself shifts — losing weight reduces BMR and NEAT; gaining increases them. Recheck and adjust intake every 4–6 weeks.