Frequently Asked Questions

Total Daily Energy Expenditure, the calories your body burns in a 24-hour period. It combines BMR (resting metabolism), the thermic effect of food, and all physical activity.

Basal Metabolic Rate, the calories your body burns at complete rest, just to keep you alive (heart, brain, organs, cell maintenance). BMR is typically 60–70% of TDEE.

Formula-based estimates miss by more than 250 kcal/day for at least half of users (per MacroFactor's 2024 dataset). Treat the number as a starting point and adjust based on 2–3 weeks of weight tracking.

Mifflin–St Jeor by default, the most validated equation for healthy adults (Am J Clin Nutr, 1990). Power Mode shows all 7 formulas side by side, including Harris–Benedict, Katch–McArdle, and Cunningham.

About 80% of users overestimate. Use the built-in 8-question lifestyle quiz ("Not sure? Take the 60-second quiz" under the activity dropdown). It outputs a precise numerical multiplier calibrated to your real lifestyle.

Enter it in Power Mode. The calculator switches from Mifflin–St Jeor to Katch–McArdle, which uses lean body mass directly and is more accurate when composition is known.

Standard starting point: 0.8–1.0 g protein per lb of body weight, then split remaining calories ~30/70 fat/carb for moderate carb. Power Mode includes a 2D selector across cut/maintain/bulk × low/moderate/high carb.

About 0.5–1% of body weight per week. Faster than that risks muscle loss and metabolic adaptation. A 500 kcal/day deficit produces about 1 lb of weight loss per week for most adults.

About 0.5 lb per month for trained men, half that for trained women, faster for absolute beginners ("newbie gains"). A 250–500 kcal surplus with high protein (1.6–2.2 g/kg) and progressive resistance training is the standard recipe.

Water weight, glycogen, sodium, gut contents, and hormonal cycle can swing weight by ±2–4 lb day-to-day without any change in fat or muscle. Weigh weekly at the same time, or take a 7-day moving average.

Yes. BMR drops as body mass decreases. Recalculate every 10–15 lb of change. Also, metabolic adaptation (a small extra drop beyond what the formula predicts) is real for many people during sustained deficits.

The same formulas apply, with sex-specific constants built in. Life-stage adjustments matter: luteal phase adds ~150 kcal/day, pregnancy +0/+340/+452 by trimester, breastfeeding +330–500 with a 1,800 kcal floor. See our /tdee-for-women/ guide.

Yes. The URL stores your inputs as query parameters. Click "Copy share link" and the recipient sees your exact configuration pre-filled.

Different calculators use different default formulas (Mifflin vs. Harris-Benedict can differ by 50–80 kcal), different activity-factor scales, and different default body-fat assumptions. Match the formula and activity scale across tools for apples-to-apples comparison.

Our editorial team. Every page that displays health-related calculations cites the primary source (paper + PMID + journal). See /methodology/ for the full derivation of every formula we use.