Free tool
Calorie calculator: how many calories should you eat a day?
Enter your details to get a daily calorie target for losing, maintaining or gaining weight — plus a macro breakdown to go with it. No sign-up, nothing stored.
Last reviewed August 30, 2026 by the Caloris nutrition product team.
Calorie calculator
Your result
1,496kcal / day
lose weight steadily — About 0.45 kg (1 lb) per week. Your estimated maintenance is 1,996 kcal and your BMR is 1,452 kcal.
Suggested macro split (30/40/30)
- Protein
- 112 g · 30%
- Carbs
- 150 g · 40%
- Fat
- 50 g · 30%
How this calorie calculator works
The calculator runs two steps. First it estimates your basal metabolic rate — the calories your body burns at complete rest keeping your heart, brain, kidneys and liver running — using the Mifflin-St Jeor equation:
- Men: (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5
- Women: (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161
Then it multiplies your BMR by an activity factor to get total daily energy expenditure, or TDEE — what you actually burn on a normal day. Finally it applies your goal: minus 500 calories for steady weight loss, minus 250 for gradual loss, zero for maintenance, and the equivalent additions for weight gain. If you want to see the maintenance figure on its own, use the TDEE calculator.
How fast will you actually lose weight?
Roughly 7,700 calories equals a kilogram of body fat (about 3,500 per pound), which is where the standard deficit guidance comes from. The real rate is messier — water weight, glycogen and digestive contents all move the number on the scale independently of fat — but over four to six weeks the maths holds up well enough to plan with.
| Daily deficit | Weekly loss | Monthly loss | Practical note |
|---|---|---|---|
| 250 kcal/day | ~0.23 kg (0.5 lb) | ~1 kg (2 lb) | Easiest to sustain; barely noticeable day to day |
| 500 kcal/day | ~0.45 kg (1 lb) | ~2 kg (4 lb) | The standard recommendation for most people |
| 750 kcal/day | ~0.68 kg (1.5 lb) | ~3 kg (6 lb) | Requires careful protein intake to protect lean mass |
| 1,000 kcal/day | ~0.9 kg (2 lb) | ~4 kg (8 lb) | Only appropriate at higher starting weights, ideally supervised |
The part calculators cannot do for you
Knowing your target is the easy half. The hard half is knowing what you actually ate, and this is where most calorie counting quietly falls apart: people under-report intake substantially, not through dishonesty but because oils, sauces, drinks and portion sizes are genuinely hard to eyeball.
That is the problem an AI calorie counter is built to solve. Instead of estimating a portion in your head and hunting for the closest database entry, you photograph the plate and the app proposes the entry for you. Caloris takes about three seconds per meal, which matters more than it sounds: the accuracy of a food log is dominated by whether you keep it at all.
After you have your number
- Set the target in an app you will actually open. Consistency beats precision by a wide margin.
- Split it into macros. Use the macro calculator to turn the calorie figure into protein, carbohydrate and fat targets. Protein is the one to protect when you are in a deficit.
- Track for two full weeks before judging it. One bad weigh-in is noise. A flat two-week average is a signal.
- Adjust by 10%, not by half. If weight has not moved after three weeks of consistent logging, drop the target by about 10% rather than making a dramatic cut.
Frequently asked questions
How many calories should I eat a day to lose weight?
Most people lose weight at a rate of about 0.45 kg (1 lb) per week on a deficit of roughly 500 calories a day below maintenance, and about 0.23 kg (0.5 lb) per week on a 250-calorie deficit. Start from your maintenance figure — the calculator above works it out from your height, weight, age, sex and activity level — then subtract. Do not drop below roughly 1,500 calories a day for men or 1,200 for women without medical supervision.
Which formula does this calorie calculator use?
It uses the Mifflin-St Jeor equation to estimate basal metabolic rate, then multiplies that by a standard activity factor between 1.2 (sedentary) and 1.9 (extremely active) to get total daily energy expenditure. Mifflin-St Jeor is the equation most commonly recommended for adults because it has been validated more widely than the older Harris-Benedict formula.
How accurate is a calorie calculator?
A calorie calculator gives you a population average, not a personal measurement. Real energy expenditure varies by roughly 10% either side of the predicted figure because of differences in lean mass, hormones, non-exercise movement and digestion. Treat the number as a starting point: track your intake and weight for two to three weeks, then adjust the target based on what actually happened to your weight.
Should I eat back the calories I burn from exercise?
Not usually. The activity multiplier in this calculator already includes your typical training, so adding exercise calories on top double-counts them. Fitness trackers also tend to over-estimate calories burned. If you have an unusually heavy training day, adding a modest amount back is reasonable, but do not add all of it.
Why is my weight not moving even though I hit my calorie target?
The two most common causes are under-reported intake and over-estimated activity. Cooking oils, sauces, drinks and untracked bites add up quickly, and most people choose an activity level one step higher than their week really justifies. Weigh yourself at the same time daily and compare weekly averages rather than day-to-day numbers, since water weight can hide fat loss for a fortnight at a time.
Is a 1,200 calorie diet safe?
1,200 calories a day is the conventional lower limit for adult women and 1,500 for adult men, and even those figures are intended for short periods rather than indefinite use. Below that it becomes hard to meet micronutrient needs and lean mass loss accelerates. If your calculated target falls under the floor, extend your timeline rather than cutting deeper, and speak to a doctor or dietitian first.
Hit your calorie target without the data entry
A target only works if you log against it. Caloris turns a photo of your plate into calories and macros in about three seconds — free on Google Play.
- Free to download
- Photo, barcode or text logging
- No credit card to start
10,000+ downloads · Rated for 3+
Keep reading
- TDEE CalculatorTotal daily energy expenditure and BMR.
- Macro CalculatorProtein, carb and fat targets for your goal.
- AI Calorie CounterHow AI calorie counting works, and how accurate it is.
- For Weight LossSet a calorie deficit and track it without the busywork.
- Best AI Calorie Counter AppsHow the leading AI trackers compare in 2026.