TDEE Calculator — Find Your Maintenance Calories
Find your maintenance calories, then let me show you what to do with them.
TDEE calculator — Mifflin-St Jeor
| Activity level | TDEE |
|---|
Next step: take this number to the cutting calculator or the bulking calculator — or let me plan your week free.
What TDEE actually is
TDEE stands for total daily energy expenditure. In plain words: every calorie your body burns in a day, added up.
It has two parts. The first is your BMR, your basal metabolic rate. That’s what you’d burn lying still in bed for 24 hours: heart beating, lungs working, brain running, muscle quietly repairing itself. For most lifters that’s the biggest share of the bill, somewhere around 60–70% of it. The second part is everything you do on top. Walking to the car. Training. Carrying groceries. Digesting food. Fidgeting through a long meeting.
The calculator above estimates your BMR with the Mifflin-St Jeor equation, then multiplies it by an activity factor to get your TDEE. Eat around that number and your weight holds steady. That’s maintenance. Everything else you’ll ever do with food — cutting, building, holding — is built on top of that one number.
The equation under the hood: Mifflin-St Jeor
No secret sauce here. The math is public science, published in 1990 and built from lab measurements of 498 real people [1]. Here it is, if you want to check my work with a pencil:
| Sex | BMR (calories per day) |
|---|---|
| Men | (10 × weight in kg) + (6.25 × height in cm) − (5 × age in years) + 5 |
| Women | (10 × weight in kg) + (6.25 × height in cm) − (5 × age in years) − 161 |
Weight goes in as kilograms, height as centimeters. If you think in pounds and inches, divide pounds by 2.2 and multiply inches by 2.54, and your pencil math will line up with the calculator above.
Why Mifflin-St Jeor and not Harris-Benedict
Harris-Benedict is the older, more famous formula. It dates to 1919, and plenty of calculators still run on it. We don’t, for one simple reason: when the American Dietetic Association reviewed the common prediction equations against metabolic rates measured in a lab, Mifflin-St Jeor came out on top. It landed within 10% of the measured number for more people than any other formula, and when it missed, it missed by less [2].
I’ll be straight with you: within 10% still means a man with a true maintenance of 2,600 could get an estimate anywhere from about 2,350 to 2,850. No equation reads your body from four numbers. This is simply the most honest one we have, and honest is the standard in my kitchen.
The activity multipliers, in real training terms
The multiplier is where most men go wrong, so let’s put real life next to each number.
| Multiplier | Label | What it looks like |
|---|---|---|
| 1.2 | Sedentary | Desk job, no real training, under ~5,000 steps a day |
| 1.375 | Light | Training 1–3 days a week, desk life otherwise |
| 1.55 | Moderate | Lifting 3–5 days a week plus normal daily walking |
| 1.725 | Hard | Training 6–7 days a week, or a job on your feet plus the gym |
| 1.9 | Very hard | Heavy physical work and serious training — framers, farmhands, two-a-days |
Now the part I need you to read twice: nearly everyone picks too high. An hour of lifting is one hour out of 24. If you train four days a week and sit at a desk the rest of the time, you’re around 1.5, maybe 1.55. Not 1.725. In my experience most lifters live between 1.5 and 1.7, and the men who truly live at 1.9 aren’t reading calculator pages. They’re asleep by nine.
Pick the lower multiplier. Adding 150 calories in two weeks feels great. Staring at a scale that won’t move feels terrible. Choose the mistake you’d rather correct.
How I use a TDEE number in my kitchen
When I was prepping for the Swedish Grand Prix, my spreadsheet gave me one maintenance number. Three weeks of morning weigh-ins said it was about 200 calories lower. The scale won that argument, and it should win yours too.
The calculator writes the first draft. Your body edits it.
Here’s the routine I’ve used since my competing days:
- Eat at your calculated TDEE for two to three weeks. Track honestly. The oil in the pan and the handful of peanuts by the fridge count.
- Weigh in every morning — same time, after the bathroom, before food or coffee. Then average each week. Single days lie; weekly averages tell the truth.
- Compare and adjust. Weight steady? You’ve found your real maintenance. Drifting up or down? Move intake by 100–200 calories and give it another two weeks.
One more honest note. I’m 40 now. My maintenance is lower than it was at 25, and much lower than the 16-year-old who stepped off the plane from Stockholm and ate half of Chicago in his first winter. That’s not a tragedy, it’s arithmetic. You feed the body you have today, not the one from an old photo.
What to do with your number
Maintenance on its own is only a landmark. The point is where you go from it:
- Want to get leaner? Eat under it. My cutting calculator sets a deficit that’s steep enough to work and gentle enough to keep your strength.
- Want to build? Eat over it, modestly. The bulking calculator keeps the surplus small enough that you’re building muscle, not a gut.
- Not sure yet? Eat at maintenance and get your protein in order first. My free 7-day plan lays out a week of eating so you don’t have to think about it.
And whichever direction you pick, the food should be worth eating. The recipe shelf is full of high-protein plates that fit a tight calorie budget without tasting like punishment.
That’s the whole reason this kitchen exists.
Common mistakes with a TDEE number
- Treating it as gospel. It’s an estimate with a known error range. Let the scale outvote the formula every time.
- Double-counting exercise. The activity multiplier already includes your training. If you then eat back the 600 calories your watch claims you burned, you’ve paid for the same workout twice. The watch was probably exaggerating anyway.
- Recalculating every few days. Your TDEE didn’t change between Monday and Friday. Chasing a fresh number every time the scale twitches is how men end up confused and hungry. Set it, test it, adjust from results.
- Picking the multiplier you wish were true. Optimism belongs in your training log, not your activity factor.
- Judging by three days. Water, sodium, carbs, and a hard leg day swing the scale by a couple of kilos overnight. Weeks tell the truth. Days gossip.
I’m a cook and a lifter, not a doctor. These formulas estimate energy needs for healthy adults. If you have a medical condition, a history of disordered eating, or take medication that affects weight, talk with your physician before changing how you eat.
TDEE questions, answered straight
Is a TDEE calculator accurate?
Close, not exact. In the validation research, Mifflin-St Jeor landed within 10% of measured resting metabolic rate for most people — roughly ±250 calories on a 2,500-calorie day — and some folks still fall outside that band. Use it as a starting line, confirm it with two to three weeks of weigh-ins, and trust your own data over any formula. Including mine.
How often should I recalculate my TDEE?
When something real changes: bodyweight moves by 4–5 kg (about 10 lb), you take a job on your feet, your training doubles. Otherwise leave it alone and steer with your weekly average weight. The scale updates you faster than the formula ever will.
Why am I not losing weight eating under my TDEE?
Usually one of three things. The estimate ran high — a too-generous activity multiplier is the classic. The intake count runs low — cooking oil, sauces, bites and licks add up faster than most men admit. Or water is hiding the loss — stress, sodium, and a new training block hold water for weeks. Tighten the tracking, drop 150–200 calories, give it three more weeks. I’ve never seen honest tracking and patience fail together.
Does TRT change your TDEE?
A bit, and not in the way the forums promise. I’ve been on TRT since I was 35, and the honest answer is this: more lean mass burns a few more calories at rest, and better recovery lets you train more, which raises the activity side. It doesn’t rewrite the math, and it doesn’t grant free calories — I count the same way I did before. And to be clear, that’s my lived experience, not medical advice. TRT is a conversation for you and your doctor.
Should I eat the same on rest days?
I do, and I’d suggest you do too. TDEE is a daily average: the multiplier already spreads your training across all seven days. One target every day keeps the shopping, the prep, and your head simple. If you’d rather cycle calories, that’s fine — the weekly total is what decides.
References
- Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr. 1990;51(2):241–247. PubMed: 2305711
- 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. PubMed: 15883556