TDEE Calculator
Convert your basal metabolic rate (BMR) into total daily energy expenditure (TDEE) by multiplying by an activity factor. The single number to eat at for maintenance, to subtract from for fat loss, or to add to for muscle gain.
Last updated: May 2026
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About this calculator
TDEE is the total calories you burn over a 24-hour day, including resting energy (BMR) plus the cost of every activity from typing at a desk to running a marathon. The formula is TDEE = BMR × activity factor, where the activity factor is a single coefficient that compresses all your daily movement into a multiplier on resting metabolism. Standard factors: 1.2 (sedentary — desk job, no exercise), 1.375 (light — light exercise 1–3 days/week), 1.55 (moderate — exercise 3–5 days/week), 1.725 (heavy — hard exercise 6–7 days/week), 1.9 (very heavy — twice-daily training or physical job). These multipliers come from the Harris-Benedict tradition and approximate the combined contribution of NEAT (non-exercise activity thermogenesis — fidgeting, standing, walking around), exercise activity thermogenesis (planned workouts), and TEF (thermic effect of food — ~10% of TDEE for typical diets). Variables: bmr is your calculated or measured basal metabolic rate in kcal/day; activity is the multiplier reflecting your overall activity level. Edge cases: activity factor must match how active you actually are — over-classifying yourself ("I think I'm moderately active") inflates TDEE and is the most common reason people fail at fat loss. Studies using doubly-labelled water (the gold standard for measuring real energy expenditure) consistently show that self-reported activity overstates true expenditure by 10–30%. Athletes with two daily training sessions plus a physical job might legitimately reach 1.9 or even higher; most office workers who go to the gym 3x/week sit comfortably at 1.4–1.5, not 1.55. Treat the TDEE number as a starting hypothesis to refine against actual weight change over 2–3 weeks, then adjust by ±100–200 kcal/day until weight is stable.
How to use
Example 1 — Moderately active man. Your BMR is 1850 kcal/day (calculated for a 30-year-old, 80 kg, 180 cm male). You exercise 4 times per week — that's moderately active. Enter BMR = 1850, Activity = Moderate (1.55). TDEE = 1850 × 1.55 = 2867.5 ≈ 2868 kcal/day. ✓ To lose ~0.5 kg per week, eat at a 500-kcal deficit ≈ 2368 kcal/day; for slow muscle gain, eat at a 200–300 kcal surplus ≈ 3100 kcal/day. Example 2 — Sedentary office worker. Your BMR is 1400 kcal/day and you have a desk job with no structured exercise. Enter BMR = 1400, Activity = Sedentary (1.2). TDEE = 1400 × 1.2 = 1680 kcal/day. ✓ This is maintenance; eating at this level should keep weight stable. Note how much smaller this is than the active person's TDEE despite a smaller BMR — activity multipliers compound. A common pitfall is the same person estimating themselves at 1.55 because they "walk a lot at work", which inflates TDEE by over 350 kcal/day — enough to prevent weight loss entirely.
Frequently asked questions
What's included in the activity multiplier?
Three components: (1) NEAT — non-exercise activity thermogenesis — fidgeting, standing, walking from your desk to the printer, household chores, gestures while talking. NEAT is the largest source of variation between individuals; some people burn 800 kcal/day in NEAT, others only 200. (2) EAT — exercise activity thermogenesis — calories burned in deliberate workouts (running, lifting, cycling). For a typical recreational exerciser, EAT is 200–500 kcal/day averaged over the week. (3) TEF — thermic effect of food — the energy your body uses to digest, absorb, and store nutrients, roughly 10% of caloric intake (higher for protein, lower for fat). The multipliers (1.2, 1.375, 1.55, etc.) bundle all three into a single coefficient that's easy to use but hides a lot of individual variation. If you want more precision, track everything with a fitness wearable for 2–3 weeks and compute your personal multiplier as logged calories burned / BMR.
How accurate are the standard activity multipliers?
They're rules of thumb that frequently overstate real expenditure, especially for people who self-classify as "moderately active" or higher. Studies using doubly-labelled water (the gold-standard isotope method for measuring real energy expenditure) consistently show self-reported activity overestimates true expenditure by 10–30%. The mechanism: people overestimate how much they exercise, and NEAT often drops in compensation when structured exercise increases (your body subconsciously fidgets less on heavy training days). A reliable approach is to start with the calculated TDEE, eat at that level for 2–3 weeks while tracking weight, then adjust by ±100–200 kcal/day depending on whether weight is stable, rising, or falling. The number the calculator gives you is a starting hypothesis to test, not a fixed truth.
How do I use TDEE to lose weight or gain muscle?
For fat loss, eat below TDEE — a 500 kcal/day deficit produces roughly 0.5 kg/week loss (since ~3500 kcal ≈ 0.5 kg body fat), and a 1000 kcal/day deficit produces ~1 kg/week. Deficits larger than 1000 kcal/day are not sustainable for most people and often cause muscle loss; for very lean targets (sub-15% body fat for men, sub-22% for women) deficits should be smaller — 250–500 kcal/day — to preserve muscle. For muscle gain, eat above TDEE by 200–500 kcal/day combined with progressive strength training; gaining faster than ~0.25 kg/week of muscle is generally impossible and the surplus just becomes fat. Recompute TDEE every 5–10 kg of weight change because BMR shifts with body mass. Track weekly average weight rather than daily readings to filter out water and digestive noise.
What are the most common mistakes people make using TDEE?
The first is choosing too high an activity multiplier — most people who say they're "very active" are really lightly to moderately active when measured objectively, so they overeat thinking they're at maintenance. The second is treating the output as exact: real metabolic rates vary 10–15% between individuals of identical age, sex, height, and weight, so the calculator is a starting estimate, not a diagnosis. The third is forgetting that BMR drops as you lose weight (you burn less because there's less of you), so the maintenance number you calculated 10 kg ago is no longer valid. The fourth is ignoring tracking error in food intake: under-reporting is so universal in nutrition studies it has its own name (the "memory deficit"), typically 20–40% in self-reported logs. The fifth is swinging wildly between large deficits and surpluses; sustained modest deficits of 300–500 kcal/day produce far better long-term results than 1000+ kcal/day crash dieting followed by binges.
When should I not use this calculator?
Don't use it under 18 — children and adolescents have different metabolic rates and require pediatric equations plus an allowance for growth. Skip it during pregnancy and lactation, which add roughly 300 and 500 kcal/day to maintenance respectively, and require dedicated calculators. It's unreliable for people with significant medical conditions affecting metabolism — untreated thyroid disorders, recent major surgery, severe burns, cancer cachexia, eating-disorder recovery — those situations need clinical indirect calorimetry. It's also a poor fit at body composition extremes: elite bodybuilders with very high lean mass underestimate; severely obese individuals (BMI > 40) tend to overestimate because the linear formula doesn't adjust for the lower metabolic activity of excess adipose. For any of these populations, a registered dietitian or sports medicine physician should interpret needs in context rather than relying on a single web tool. Finally, don't use TDEE as a hard cap — appetite, satiety, and sustainability matter more than hitting an exact number every day.