Pensum
TDEE calculator
Your maintenance calories, BMR and a macro split, from the same equations Pensum sets your first targets with.
A formula is only a starting estimate
Every TDEE calculator, this one included, guesses your metabolism from four numbers: height, weight, age and sex. It then multiplies that by an activity factor you picked from a list. A 2005 systematic review of the common equations found that even Mifflin-St Jeor, the most reliable of them, still produces noteworthy errors for individuals.1 Add the activity guess on top, and two people with identical stats can burn a couple of hundred calories a day apart.
That gap is large enough to decide whether a cut works. Use the number above to get started, then expect it to be corrected.
After day one, Pensum measures your expenditure
Pensum starts you on exactly this number. As you log food and weigh in, it compares what you ate with how your weight trend moved and works out what you actually burn. Water swings and missed days are smoothed out, and within a few weeks the formula is replaced by a measured figure that keeps updating. Your calorie target follows it.
The method is published in full, every constant included, at how Pensum measures your expenditure. The measured expenditure is part of the free app.
How this calculator works
Many calculators run Mifflin-St Jeor from 1990. Pensum uses a newer regression equation for BMR. Its weight term grows more slowly than body weight, so the estimate doesn't run away for heavier people the way a flat 10 kcal per kilogram does. W is weight in kg, H is height in cm, and S is 0 for male, 1 for female and 0.5 for other:
past 60, each further year counts 4.9 instead of 1.96
TDEE = BMR × activity factor
The weekly rate converts to calories at 7,700 kcal per kilogram (about 3,500 per pound), so 0.5 kg a week is 550 kcal a day under or over maintenance.2 A cut never goes below 1,200 kcal, or below maintenance itself if yours is lower than that.
Protein and fat scale with lean mass, estimated from height, weight and sex with the Boer equation. Protein recommendations for lifters in a deficit are often given per kilogram of lean mass, since fat mass has no use for the extra protein.3 Protein is 1.9 g per kg of lean mass at maintenance, 2.0 when gaining, and 2.2 rising to 2.8 while cutting, depending on how fast you cut relative to your body weight. It never exceeds 2.2 g per kg of total body weight. Fat is 0.8, 1.0 or 1.2 g per kg of lean mass for losing, maintaining and gaining. Carbs get the calories that are left.
Questions
What is TDEE?
TDEE stands for total daily energy expenditure: the calories your body uses in a full day. It adds up your resting metabolism (BMR), the energy spent digesting food, and everything you do on your feet, from workouts to walking to the kitchen. Eat at your TDEE and your weight holds steady over time.
What is the difference between BMR and TDEE?
BMR (basal metabolic rate) is what you would burn lying still all day: breathing, circulation, keeping warm. TDEE is BMR multiplied by an activity factor, from 1.2 for a desk job with no exercise up to 1.9 for hard daily training or a physical job. Calorie targets are set from TDEE.
How accurate is a TDEE calculator?
It is a reasonable first guess and nothing more. A 2005 systematic review found that even Mifflin-St Jeor, the most reliable of the common equations, still produces noteworthy errors for individuals, and the activity factor stacks a second guess on top. Two people with identical stats can differ by a couple of hundred calories a day. The only way to know your number is to measure it: log what you eat, weigh yourself, and read the result off your weight trend.
How many calories should I eat to lose weight?
Start from your TDEE and subtract a deficit. The usual conversion is about 7,700 kcal per kilogram of body weight (3,500 per pound), so losing 0.5 kg a week means eating roughly 550 kcal a day under maintenance. This calculator never sets a cut below 1,200 kcal. The conversion overstates long-term loss because expenditure falls as you get lighter, which is why your maintenance number should be re-measured as you go.
Which activity level should I pick?
Count the days a week you train or do sustained physical work: none is sedentary, 1 to 3 is light, 3 to 5 is moderate, 6 to 7 is very active, and extra active is for hard training twice a day or a manual job. Most people overrate their activity, so when you are between two levels, take the lower one.
How much protein should I eat?
This calculator scales protein on lean mass: 1.9 g per kg of lean mass at maintenance, 2.0 when gaining, and 2.2 to 2.8 while cutting, rising with how fast you cut. It never goes above 2.2 g per kg of total body weight. Lean mass is estimated from height, weight and sex with the Boer equation.
Does this match what the Pensum app shows?
Yes. The calculator runs the same BMR equation, activity factors, goal math and macro rules the Pensum app uses to set your first targets from height and weight (if you enter a body fat percentage in the app, it switches to a body-composition equation). Within a few weeks of logging, Pensum replaces the formula with your measured expenditure, and that measurement is part of the free app.
References
- 1. Frankenfield D, Roth-Yousey L, Compher C. Comparison of predictive equations for resting metabolic rate in healthy nonobese and obese adults: a systematic review. Journal of the American Dietetic Association, 2005;105(5):775-789. doi:10.1016/j.jada.2005.02.005
- 2. Hall KD, Chow CC. Why is the 3500 kcal per pound weight loss rule wrong? International Journal of Obesity, 2013;37(12):1614. doi:10.1038/ijo.2013.112. The fixed conversion overstates long-term loss because expenditure falls with body mass.
- 3. Helms ER, Aragon AA, Fitschen PJ. Evidence-based recommendations for natural bodybuilding contest preparation: nutrition and supplementation. Journal of the International Society of Sports Nutrition, 2014;11:20. doi:10.1186/1550-2783-11-20