Calorie calculator
Find out how many calories you burn in a day, and what a sensible target looks like if you want to lose or gain. Same formula and same safety limits as the Kalorea app.
- Resting burn (BMR)
- 1,379 kcal
- Lose gently1,870 kcal
- Lose steadily1,737 kcal
- Lose at the safe maximum1,603 kcal
- Keep your weight2,137 kcal
- Gain2,458 kcal
We don't suggest a calorie deficit under 18 or with a BMI below 18.5. Talk to a doctor about your goals.
What the numbers mean
Resting burn (BMR) is what your body spends doing nothing at all: breathing, keeping warm, running your organs. It's usually 60 to 70% of what you burn in a day.
Maintenance adds everything else: walking around, work, training. Eat this much and your weight stays roughly where it is. It's the number most people mean when they ask how many calories they should eat a day.
Targets are maintenance minus a deficit to lose weight, or plus a surplus to gain. We never go below your resting burn, and we cap the pace at 1% of body weight a week.
How to use it in real life
Pick a target and live with it for two to three weeks before judging it. Daily weight jumps by a kilo or more from water and salt alone; the weekly average is what tells the truth.
If the average doesn't move after three weeks, the problem is usually counting, not the formula: oil, drinks and snacks are where calories hide. That is exactly what photo logging with a range helps you see.
Maintenance calories by age and activity
Calories a day to keep your weight, from the same formula. Women: 165 cm (5 ft 5 in), 65 kg (143 lb). Men: 178 cm (5 ft 10 in), 80 kg (176 lb). Your own number depends on your height and weight, so use the calculator above for it.
Women
| Age | Sitting | Walking | Train 2-3× | Train daily |
|---|---|---|---|---|
| 20 | 1,704 | 1,953 | 2,201 | 2,450 |
| 25 | 1,674 | 1,918 | 2,163 | 2,407 |
| 30 | 1,644 | 1,884 | 2,124 | 2,364 |
| 35 | 1,614 | 1,850 | 2,085 | 2,321 |
| 40 | 1,584 | 1,815 | 2,046 | 2,277 |
| 45 | 1,554 | 1,781 | 2,008 | 2,234 |
| 50 | 1,524 | 1,747 | 1,969 | 2,191 |
| 55 | 1,494 | 1,712 | 1,930 | 2,148 |
| 60 | 1,464 | 1,678 | 1,891 | 2,105 |
| 65 | 1,434 | 1,643 | 1,853 | 2,062 |
| 70 | 1,404 | 1,609 | 1,814 | 2,019 |
Men
| Age | Sitting | Walking | Train 2-3× | Train daily |
|---|---|---|---|---|
| 20 | 2,181 | 2,499 | 2,817 | 3,135 |
| 25 | 2,151 | 2,465 | 2,778 | 3,092 |
| 30 | 2,121 | 2,430 | 2,740 | 3,049 |
| 35 | 2,091 | 2,396 | 2,701 | 3,006 |
| 40 | 2,061 | 2,362 | 2,662 | 2,963 |
| 45 | 2,031 | 2,327 | 2,623 | 2,920 |
| 50 | 2,001 | 2,293 | 2,585 | 2,876 |
| 55 | 1,971 | 2,258 | 2,546 | 2,833 |
| 60 | 1,941 | 2,224 | 2,507 | 2,790 |
| 65 | 1,911 | 2,190 | 2,468 | 2,747 |
| 70 | 1,881 | 2,155 | 2,430 | 2,704 |
How it's calculated
Resting burn uses the Mifflin-St Jeor equation: 10 × weight in kg + 6.25 × height in cm − 5 × age, plus 5 for men or minus 161 for women.
Maintenance is resting burn times an activity factor: 1.2 mostly sitting, 1.375 walking but no sport, 1.55 training 2 to 3 times a week, 1.725 training almost every day.
The deficit is capped by the strictest of three limits: 25% of maintenance, the gap between maintenance and resting burn, and a pace of 1% of body weight per week (1 kg of fat is counted as 7,700 kcal). “Gently” is half of that cap, “steadily” three quarters.
A surplus for gaining weight is 15% of maintenance.
Example: a 30-year-old woman, 168 cm, 64 kg, training 2 to 3 times a week. Resting burn is 10 × 64 + 6.25 × 168 − 5 × 30 − 161 = 1,379 kcal. Maintenance is 1,379 × 1.55 = 2,137 kcal.
Questions
Why Mifflin-St Jeor?
In studies comparing the common equations, Mifflin-St Jeor most often lands closest to measured resting burn in healthy adults. It's still an estimate: real burn varies from person to person by about 10%.
Why is there a cap on the deficit?
Eating far below your needs is hard to sustain, and losing faster than about 1% of body weight a week tends to cost muscle, not just fat. The cap keeps the plan realistic.
Should I eat back the calories from exercise?
The activity level already counts your regular training. Pick the level that matches a normal week rather than adding workouts on top.
Let the app keep score
Kalorea sets your target with this formula and then counts every meal from a photo, so you can see each day where you stand.
Calorie deficit calculator
A safe daily deficit and how long your goal takes.
Macro calculator
Protein, fat and carbs in grams for your target.
BMI calculator
Your BMI and the healthy range for your height.
Calories burned calculator
Calories you burn walking, running, cycling or swimming.
Steps to calories calculator
Steps to calories burned, or calories to steps.