How is TDEE calculated?
First we estimate your BMR with the Mifflin-St Jeor equation. Then we multiply it by an activity factor between 1.2 and 1.9.
Men: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5
Women: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161
TDEE = BMR × activity factor
Example: a 30 year old man, 180 cm and 80 kg, has a BMR of 1,780 kcal. If he trains three to five times a week (factor 1.55), his TDEE is about 2,759 kcal.
How accurate is a TDEE calculator?
It is a good first guess, not a measurement. A review of the common equations found Mifflin-St Jeor the most reliable, landing within 10 percent of measured resting metabolism for most adults. The activity factor adds more uncertainty than the formula itself.
The practical fix: eat at your target for two to three weeks and log what you eat. If your weight trend moves faster or slower than planned, adjust by 100 to 200 kcal. That is the part myCalCoach on Telegram takes off your hands: send a photo of each meal and it keeps the running total.
How much protein should I eat?
The calculator shows 1.6 g per kg of body weight. A 2018 meta-analysis of resistance training studies found that gains in muscle mass levelled off around this amount. When you are eating less to lose fat, staying near it helps you keep muscle.
Common questions
What is the difference between BMR and TDEE?
BMR (basal metabolic rate) is what your body burns at complete rest: breathing, circulation, keeping warm. TDEE adds everything else, from walking to the car to a hard workout. For most people TDEE is 20 to 60 percent higher than BMR.
Should I eat at my TDEE to lose weight?
No. Eating at your TDEE keeps your weight roughly stable. To lose weight you eat below it. A deficit of about 500 kcal a day is a common starting point and works out to roughly 0.5 kg (1 lb) per week.
Which activity level should I choose?
Most people overestimate. If you sit at work and train three times a week, "lightly active" is usually closer than "moderately active". When in doubt, pick the lower one and adjust after two or three weeks.
How often should I recalculate?
Every 4 to 5 kg (about 10 lb) of change, or when your training changes a lot. A lighter body burns less, so the same intake slowly stops working.
Sources
- Mifflin MD, St Jeor ST, et al. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr. 1990;51(2):241-247.
- Frankenfield D, Roth-Yousey L, Compher C. Comparison of predictive equations for resting metabolic rate in healthy nonobese and obese adults: a systematic review. J Am Diet Assoc. 2005;105(5):775-789.
- Morton RW, et al. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength. Br J Sports Med. 2018;52(6):376-384.
This calculator gives general estimates and is not medical advice. If you are pregnant, under 18, have a medical condition or a history of disordered eating, talk to a doctor before changing your diet.