Total daily energy expenditure (TDEE) is how many Calories you burn in a day: your resting metabolism plus everything you do. Eating about your TDEE keeps weight stable, which is why it is also called maintenance calories. It is estimated as BMR × physical activity level (PAL). For a 35-year-old woman who is 165 cm and 68 kg with a light activity level (1.6), TDEE is about 2,200 Calories a day.
The NIDDK Body Weight Planner, built by NIH researchers, describes typical PAL values from 1.4 (sedentary) to 2.5 (very active). Its default of 1.6 describes someone who does very light activity at school or work, mostly sitting, plus moderate activity such as walking or cycling at least once a week. This calculator uses the Mifflin–St Jeor equation for BMR and lets you pick a PAL in that range.
How to use the tdee calculator
- Enter sex, age, height and weight (US or metric).
- Pick the activity level that matches a typical week, not your most active day. Most people overestimate.
- Read maintenance calories, plus starting points for gradual loss or gain.
- Track your weight for 2–3 weeks at that intake and adjust: if weight is steady, you have found your real maintenance level.
Formula
PAL (physical activity level) is the ratio of total to resting energy expenditure. The NIDDK planner gives a typical range of 1.4–2.5; the steps 1.75, 1.9 and 2.2 in the menu are our planning points within that range, not official categories.
Worked example
Woman, 35, 165 cm, 68 kg, light activity (PAL 1.6).
- BMR = 10 × 68 + 6.25 × 165 − 5 × 35 − 161 = 680 + 1,031.25 − 175 − 161 = 1,375 Calories/day.
- TDEE = 1,375 × 1.6 = 2,200 Calories/day.
- At a moderate level (1.75) it would be about 2,407 Calories/day.
Turning TDEE into a plan
To lose weight you eat below TDEE, and to gain you eat above it. A deficit of about 500 Calories a day is a common starting point, but research by NIH scientists (Hall et al., The Lancet, 2011) shows weight loss slows over time as the body adapts, so the simple "3,500 Calories per pound" rule overstates long-term results. The calorie deficit calculator estimates a timeline. The macro calculator splits your calories into protein, carbohydrate and fat within the National Academies' recommended ranges.
The NIDDK planner also warns that it does not apply to people under 18 or to pregnant or breastfeeding women; the same limits apply here.
Caveats and assumptions
- Equations estimate an average. Real TDEE can differ by a few hundred Calories; adjust from your actual weight trend.
- Activity levels are approximate. Fitness-tracker calorie counts are also estimates.
- Not for people under 18, or during pregnancy or breastfeeding. Not medical advice.
Frequently asked questions
How many calories do I burn a day?
Multiply your BMR by an activity level. A 35-year-old woman at 165 cm and 68 kg with light activity burns about 2,200 Calories a day.
What activity level should I choose?
Pick the level that matches a typical week. The NIDDK planner describes 1.4 as sedentary and 1.6 as mostly sitting at work plus moderate activity at least once a week.
What is the difference between BMR and TDEE?
BMR is energy at complete rest; TDEE adds all daily activity and digestion.
How accurate is a TDEE calculator?
It is a starting estimate. Weigh yourself regularly at a steady intake for a few weeks and adjust up or down.
What happens if I eat at my TDEE?
Eating about as many Calories as you burn should keep your weight roughly stable over time; eating less leads to weight loss and more to weight gain.
Sources
- NIDDK — Body Weight Planner — physical activity levels 1.4–2.5 and the 1.6 default description
- Mifflin MD, St Jeor ST, et al. Am J Clin Nutr 1990;51(2):241-7 (PubMed) — BMR equation
- Hall KD, et al. Quantification of the effect of energy imbalance on bodyweight. Lancet 2011 — why weight loss slows (abstract confirmed through search results)
This calculator gives general estimates for healthy adults and is not medical advice, diagnosis or treatment. Equations are averages and individuals differ. Talk to a qualified health professional before changing your diet, exercise or medication, and during pregnancy. See our disclaimer and how we build and check calculators.