Our most accurate TDEE calculator runs all 3 validated formulas simultaneously. Understanding each helps you choose the right result for your body.
The most accurate TDEE calculator formula for most adults. Validated by the American Dietetic Association as the most accurate BMR formula within ±10% for 82% of the population. Our TDEE calculator free uses this as the primary recommendation. No body composition data needed.
The original TDEE calculator formula developed in 1919, revised in 1984 by Roza and Shizgal. Harris-Benedict tends to overestimate BMR by 5% compared to Mifflin-St Jeor in modern validation studies. Still widely used in clinical settings and TDEE calculator guidelines.
The most precise formula if you know your body fat percentage. Katch-McArdle is based only on lean body mass — fat tissue burns very few calories, so accounting for it increases accuracy. Best for athletes and muscular individuals. Use with our body fat calculator.
Our free TDEE calculator and TDEE calculator free tool is more complete than tdeecalculator.net, calculator.net, and tdee.is because it runs all 3 validated formulas simultaneously (Mifflin-St Jeor, Harris-Benedict, Katch-McArdle), includes a dedicated TDEE calculator for weight loss with adjustable deficit levels, a TDEE calculator deficit display with projected weekly fat loss, a full macro breakdown, a TDEE calculator for women / TDEE calculator women with gender-specific formulas, a TDEE calculator breastfeeding mode, and a keto macro calculator mode. This is the best TDEE calculator for both beginners and experienced fitness enthusiasts.
The TDEE calculator for weight loss and TDEE calculator weight loss mode works by creating a calorie deficit: eating fewer calories than your TDEE causes your body to use stored fat for energy. The math: 1 kg of fat ≈ 7,700 calories. A daily deficit of 500 kcal = 3,500 kcal/week = approximately 0.5 kg/week of fat loss. Our TDEE calculator lose weight and TDEE calculator to lose weight mode automatically applies the 500 kcal standard deficit. The TDEE calculator deficit also shows the weekly deficit total and projected monthly progress. Never eat below your BMR — this triggers metabolic adaptation (starvation mode), muscle loss, and hormonal disruption.
35-year-old female, 170cm, 72kg, moderately active:
Mifflin-St Jeor BMR = (10×72) + (6.25×170) − (5×35) − 161 = 720 + 1,062.5 − 175 − 161 = 1,446.5 kcal BMR
TDEE = 1,446.5 × 1.55 = 2,242 kcal/day
Weight Loss Target: 2,242 − 500 = 1,742 kcal/day
Projected loss: 500 × 7 ÷ 7,700 = 0.45 kg per week (~1.8 kg/month)
Our TDEE calculator for women and TDEE calculator women applies female-specific formula constants. Women generally have lower BMR than men at the same height and weight because they carry proportionally more body fat (which burns fewer calories) and less lean muscle mass. Mifflin-St Jeor subtracts 161 for women vs +5 for men — a 166 kcal/day difference at the BMR level. Before activity multiplication, this means women's TDEE is typically 200–400 kcal lower than men of similar size. The TDEE calculator women also needs to account for hormonal cycles — luteal phase (post-ovulation) can increase BMR by 150–300 kcal. Our TDEE calculator online doesn't adjust for menstrual phase (too complex), but be aware that cycle-averaged TDEE is more accurate over 4+ weeks.
The TDEE calculator breastfeeding mode adds approximately 400–500 extra calories per day to the standard TDEE calculation. Breast milk production requires roughly 500 kcal of energy per day. Switch to the Breastfeeding tab in our calculator to see breastfeeding-adjusted TDEE and a modified weight loss target that protects milk supply. Important TDEE calculator guidelines for breastfeeding: never eat below 1,800 kcal/day. Safe weight loss while nursing: TDEE + 500 (breastfeeding) − 500 (deficit) = TDEE. This achieves very slow weight loss (~0.5 kg/month) while maintaining full milk production. The best TDEE calculator for breastfeeding women uses the Mifflin formula with the +500 lactation adjustment.
The TDEE calculator formula has two steps: Step 1 — Calculate BMR using Mifflin-St Jeor: Men: BMR = 10W + 6.25H − 5A + 5 and Women: BMR = 10W + 6.25H − 5A − 161 (W = kg, H = cm, A = age). Step 2 — Multiply by activity factor: TDEE = BMR × Activity Multiplier. For the TDEE calculator net approach (calculating from food logs vs actual activity), track calories eaten vs weight change over 4 weeks for a more precise personal TDEE. The formula-based TDEE is your starting estimate — adjust by 100–200 kcal based on real-world results over 2–4 weeks.
| TDEE Formula | Accuracy | Best For | Requires |
|---|---|---|---|
| Mifflin-St Jeor | ±10%, 82% of people | General adults | Age, height, weight |
| Harris-Benedict | ±15%, overestimates ~5% | Clinical reference | Age, height, weight |
| Katch-McArdle | ±8% (with BF%) | Athletes, muscular people | Lean body mass or BF% |
| Real-world TDEE | ±2–3% | All types | 4-week food + weight log |
TDEE accuracy tip: Formula-based TDEE calculations are starting estimates, not exact values. Track your calories and weight for 2–4 weeks using the formula result, then adjust: if losing more than expected → eat 100–200 more. If not losing → eat 100–200 less. This calibrates your personal TDEE more accurately than any formula alone. The TDEE calculator accurate result improves significantly with real-world data. Check our calorie calculator for a deeper breakdown.
Questions covering TDEE formulas, weight loss deficits, women-specific TDEE, breastfeeding, activity levels, and macro breakdown.
TDEE (Total Daily Energy Expenditure) is the total number of calories your body burns in a 24-hour period, including your basal metabolic rate (calories burned at complete rest) plus all physical activity. Our TDEE calculator online uses the two-step TDEE calculator formula: Step 1: Calculate BMR using Mifflin-St Jeor: Men = 10×weight(kg) + 6.25×height(cm) − 5×age + 5. Women = 10×weight(kg) + 6.25×height(cm) − 5×age − 161. Step 2: TDEE = BMR × Activity Multiplier (1.2 for sedentary to 1.9 for extremely active). Example: A 30-year-old woman, 165cm, 65kg, moderately active: BMR = 650 + 1,031.25 − 150 − 161 = 1,370 kcal. TDEE = 1,370 × 1.55 = 2,124 kcal/day.
Our TDEE calculator to lose weight, TDEE calculator weight loss, and TDEE calculator for weight loss work by: 1) Calculate your TDEE using our free calculator above. 2) Create a calorie deficit: eat 500 kcal below TDEE per day. 3) This produces 3,500 kcal/week deficit = ~0.5 kg/week fat loss. Per TDEE calculator guidelines: a −500 kcal/day deficit is safe and sustainable. −750 kcal is faster but harder. −1,000 kcal risks muscle loss and metabolic adaptation. NEVER eat below your BMR. Our TDEE calculator deficit mode automatically shows you −250, −500, −750, and −1,000 calorie options with projected weekly fat loss for each.
The most accurate TDEE calculator for most adults uses the Mifflin-St Jeor formula (1990). It was validated in the 2005 ADA position paper as the most accurate TDEE calculator formula, predicting BMR within ±10% for 82% of the general population. Our best TDEE calculator tool runs all three: 1) Mifflin-St Jeor — best for most people (no body composition data needed). 2) Harris-Benedict (1984 revised) — slightly overestimates by ~5%, good as a cross-check. 3) Katch-McArdle — most accurate IF you know your body fat percentage; best for athletes and muscular people. The real-world most accurate TDEE calculator method: track food calories + weight changes for 4 weeks and use the actual data to calibrate your personal TDEE.
Our TDEE calculator breastfeeding mode adds 500 extra calories to standard TDEE because breast milk production requires approximately 500 kcal/day of energy. Key TDEE calculator guidelines for breastfeeding mothers: minimum intake = 1,800 kcal/day regardless of weight loss goals. Safe weight loss while breastfeeding: take your standard TDEE, add 500 (for milk production), then subtract only 250–300 kcal deficit. This results in very slow weight loss (~0.25 kg/week) while fully maintaining milk supply. Faster weight loss risks reducing milk volume and nutritional quality. Our TDEE calculator for women breastfeeding mode applies these adjustments automatically when you select the Breastfeeding tab.
TDEE calculators differ because of 3 main factors: 1) Formula choice — Harris-Benedict overestimates BMR by ~5% vs Mifflin-St Jeor. A different formula = different result. 2) Activity multiplier rounding — some use slightly different multiplier values. 3) Rounding methods — whole numbers vs decimals. Our TDEE calculator net approach shows all 3 formulas simultaneously so you can see the range of results (typically within 50–150 kcal of each other). The most important factor: TDEE formulas have ±10–15% inherent error for individuals. Real-world calibration over 4+ weeks using actual food logs and weight changes is more accurate than any formula. Use our calculator as a starting point, not a fixed truth.
Our free TDEE calculator includes macro breakdown alongside TDEE. Recommended macro ratios by goal: Weight loss: 30–35% protein, 35–40% carbs, 25–30% fat. Maintenance: 25–30% protein, 40–45% carbs, 25–30% fat. Muscle gain: 30–35% protein, 40–45% carbs, 25–30% fat. Keto: 25–30% protein, 5–10% carbs, 60–65% fat. In grams: protein = target kcal × protein% ÷ 4. Carbs = target kcal × carb% ÷ 4. Fat = target kcal × fat% ÷ 9. Example: 1,800 kcal weight loss, 30P/40C/30F: 135g protein, 180g carbs, 60g fat. Our TDEE calculator's macro display calculates this automatically for your specific calorie target and goal.