Daily Calorie Calculator
Daily Calorie Calculator
Enter your details to find your maintenance calories (TDEE) and a target calorie goal, plus a suggested protein / carb / fat split.
Your results will appear here
after you click “Calculate calories”
Formula: Mifflin-St Jeor (BMR) multiplied by an activity factor to estimate TDEE. This is a reference estimate only and does not replace advice from a doctor or registered dietitian, especially if you have an underlying health condition or a specific goal.
Where these numbers actually come from
Every calorie number above starts with your basal metabolic rate — the energy your body spends just staying alive, before you’ve moved a muscle. Breathing, circulating blood, keeping your organs running: that’s what BMR measures. It’s usually 60 to 75% of everything you burn in a day.
We calculate it with the Mifflin-St Jeor equation, which has been the standard in clinical nutrition since it was published in 1990 and has held up better than the older Harris-Benedict formula, which tends to run high for modern adults.
10 × weight (kg) + 6.25 × height (cm) − 5 × age + 510 × weight (kg) + 6.25 × height (cm) − 5 × age − 161A 2005 validation study found this equation lands within 10% of a person’s actual measured resting metabolism about 82% of the time in healthy, non-obese adults — good enough that it’s still the default choice for dietitians today.
BMR on its own isn’t very useful, though, since almost nobody spends the whole day lying still. To get your real daily burn, we multiply it by an activity factor:
| Activity level | Multiplier | What it looks like |
|---|---|---|
| Sedentary | 1.2 | Desk job, barely any structured exercise |
| Lightly active | 1.375 | Light workouts 1–3 days a week |
| Moderately active | 1.55 | Moderate exercise 3–5 days a week |
| Very active | 1.725 | Hard training 6–7 days a week |
| Extremely active | 1.9 | Physical job on top of daily hard training |
That result is your TDEE — total daily energy expenditure. It’s the number that actually matters when you’re deciding how much to eat, because it’s what keeps your weight where it is right now.
Turning that number into an eating target
Once you know your TDEE, the goal you pick just shifts the target up or down. Staying at TDEE keeps weight roughly flat. Eating around 500 calories a day under it lines up with losing about 0.45 kg (a pound) a week, based on the old rule of thumb that 3,500 stored calories works out to roughly a pound of fat. Eating 300 to 500 calories above it supports slow, mostly lean weight gain rather than a rapid one that’s mostly water and fat.
The tool also splits your target into protein, carbs, and fat — 30/45/25 by default, which is a fine general-purpose starting point but not a rule carved in stone. Someone lifting weights four times a week and someone who mostly walks for exercise don’t need the same ratio, even at the same calorie total.
How much should you actually trust this number?
Honestly — as a starting point, quite a bit. As a precise prediction of what your body will do, less so. Mifflin-St Jeor is an estimate built from population averages, not a measurement of your specific metabolism, and things like muscle mass, hormones, and genetics all push it around in ways a formula can’t see.
The activity multipliers have a similar problem. People who train hard often don’t burn quite as much as the multiplier suggests, because the body tends to quietly claw back some of that energy elsewhere in the day — a compensation effect that’s been documented in metabolic research. And the 3,500-calorie-per-pound rule, while a handy shortcut, doesn’t hold perfectly over time either; weight loss tends to slow down the longer you stay in a deficit, even without changing anything.
None of that makes the number useless. It just means the smart way to use it is as a first guess: eat at your target for two or three weeks, watch what your weight actually does, and nudge the number by 100–150 calories if reality doesn’t match the estimate.
BMR, TDEE, deficit, surplus — keeping the terms straight
BMR is what you’d burn doing absolutely nothing. TDEE adds in digestion, daily movement, and exercise on top of that — it’s the number that reflects your actual life. A deficit means eating under your TDEE, which is what drives weight loss; a surplus means eating over it, which is what supports weight or muscle gain.
One mix-up worth avoiding: cutting calories down toward your BMR instead of your TDEE. That creates a much bigger deficit than most people intend, and it’s usually too aggressive to stick with for long.
How many calories should I eat a day?
There’s no single right answer — it comes down to your age, sex, height, weight, activity level, and what you’re trying to do. Most adults land somewhere between 1,600 and 2,800 calories a day at maintenance, but that range is wide enough that it’s worth calculating your own number rather than going by an average.
How many calories do I need to cut to lose weight?
Around 500 calories a day below TDEE is a reasonable, sustainable starting point, and it’s what this calculator sets by default when you choose “Lose weight.” Going much lower than roughly 1,200 calories a day for women or 1,500 for men isn’t generally advisable without medical guidance.
Is this calculator accurate for everyone?
It’s built for generally healthy adults. It gets less reliable for pregnant or breastfeeding women, people with metabolic or endocrine conditions, athletes carrying a lot of muscle mass, and adults over 60, where it tends to run a little high. Anyone in those groups is better off checking with a doctor or dietitian.