Fill in your details and see how many calories to eat per day for your goal, plus the split across protein, carbs and fat. No sign-up.
The number on its own does nothing. goNutriTrack logs your meals from a photo, a barcode or a search, and shows how far you are from your target in real time. Free, no ads.
Open the appIf you just want a ballpark before filling anything in, the tables below show roughly how many calories a day are needed to maintain weight, worked out with the same Mifflin-St Jeor formula this calculator uses. They assume an average build — use the calculator above for your own number.
| Age | Sedentary | Moderate | Active |
|---|---|---|---|
| 19–30 | 2,070 | 2,670 | 2,970 |
| 31–50 | 1,980 | 2,560 | 2,840 |
| 51–70 | 1,860 | 2,400 | 2,670 |
| Age | Sedentary | Moderate | Active |
|---|---|---|---|
| 19–30 | 1,660 | 2,140 | 2,390 |
| 31–50 | 1,570 | 2,030 | 2,260 |
| 51–70 | 1,450 | 1,870 | 2,080 |
These are maintenance figures for an average body at each age. Taller, heavier or more muscular people need more; shorter or lighter people need less. To lose weight you eat below these numbers, to gain you eat above — the calculator does that adjustment for you.
A couple of worked examples to show how much the details matter. A 40-year-old woman, 70 kg and lightly active, needs around 1,870 calories a day to maintain. A 35-year-old man, 80 kg and training a few times a week, sits closer to 2,700 calories a day. Same question, very different answers — which is exactly why a single “2,000 calories” rule of thumb misleads most people.
The calculation runs in three steps: first we work out how many calories you burn, then we adjust that for your goal to get how many you should eat.
This is the energy your body needs just to keep running: heart, breathing, temperature, brain. We use the Mifflin-St Jeor formula, generally considered the most reliable for healthy adults.
Men: 10 × kg + 6.25 × cm − 5 × age + 5Women: 10 × kg + 6.25 × cm − 5 × age − 161
Your BMR gets multiplied by a factor based on how much you move. The result is your TDEE — the total calories you burn across the day.
Note that this is not only about the gym. The whole day counts: if you train three times a week but spend the rest of your hours at a desk, you are closer to “light” than to “moderate”. Most people overestimate here, and that is where the disappointment two months later starts.
| Level | Multiplier |
|---|---|
| Sedentary | × 1.2 |
| Light activity | × 1.375 |
| Moderate activity | × 1.55 |
| Hard activity | × 1.725 |
| Very hard | × 1.9 |
Here TDEE becomes an intake target. For weight loss we take off 10% or 20%. For muscle gain we add 10%. For maintenance you eat what you burn — which is why the two numbers match in that case.
The calculator never drops your target below your basal metabolic rate. Eating under it for long stretches does not speed up fat loss — it costs muscle mass, energy and sleep instead.
Calories decide whether you gain or lose weight. The split between them largely decides what you gain or lose.
It depends on your sex, age, height, weight and how much you move. For most women maintenance sits around 1800-2200 calories and for most men around 2200-2800.
The calculator gives you your own number using the Mifflin-St Jeor formula.
Calorie needs fall gradually with age because resting metabolism drops. For an average-build man, maintenance is roughly 2670 calories a day at 19-30 with moderate activity, about 2560 at 31-50 and about 2400 at 51-70.
For an average-build woman the same brackets are roughly 2140, 2030 and 1870. Height, weight and activity move these up or down, so use the calculator for your own figure.
What you burn is your TDEE — an estimate of the energy your body spends across the day. What you should eat comes from that number, adjusted for your goal.
If you want to maintain, the two are identical. If you want to lose, you eat less than you burn. That is why the calculator shows both: the top number is your target, the ones below show where it came from.
Mifflin-St Jeor lands within roughly 10% for most people. So if it gives you 2400 calories, your real number sits somewhere between 2160 and 2640. It is a starting point, not a final answer.
The only way to find your real number is to eat consistently for two or three weeks and watch your weight. If it will not move while you are trying to lose, drop 150-200 calories and try again.
The most common reason is that logged calories are not eaten calories. Oil in the pan, portions judged by eye, the snacks that never make it into the diary — together those easily add 300-400 calories a day.
The second reason is overestimated activity. Try dropping one level and see what comes out.
The third is water. Scale weight moves daily with salt, carbs and hormonal cycle. Look at the weekly average, not the day.
You can, but the cost goes up. The bigger the deficit, the larger the share of the loss that comes from muscle rather than fat, and the harder it gets to hold on to the result.
For most people a 20% deficit is the balance between visible progress and something you can actually sustain.
Not necessarily. The activity multiplier already averages your week. Your body does not do daily accounting.
If you prefer, you can eat a little more on training days and a little less on the rest, keeping the weekly total the same.
The formula accounts for age and works for healthy adults. It is not suitable for children and teenagers, whose needs are driven by growth.