Calculator Inputs
Formula Used
1) Mifflin-St Jeor BMR
Men: BMR = 10W + 6.25H - 5A + 5
Women: BMR = 10W + 6.25H - 5A - 161
2) Revised Harris-Benedict BMR
Men: BMR = 88.362 + 13.397W + 4.799H - 5.677A
Women: BMR = 447.593 + 9.247W + 3.098H - 4.330A
3) Katch-McArdle BMR
Lean Body Mass = Weight × (1 - Body Fat / 100)
BMR = 370 + 21.6 × Lean Body Mass
4) Maintenance calories
Maintenance Calories = BMR × Activity Multiplier
5) BMI
BMI = Weight(kg) / Height(m)2
In these equations, W is body weight in kilograms, H is height in centimeters, and A is age in years.
How to Use This Calculator
- Select your preferred unit system.
- Choose sex and enter age.
- Enter body weight and height.
- Pick an activity level that matches your average week.
- Choose a formula or leave it on auto select.
- Enter body fat percentage if you want Katch-McArdle support.
- Set carbohydrate, protein, and fat percentages totaling 100.
- Click the calculate button to see maintenance calories above the form.
- Use the chart to compare activity-based calorie changes.
- Download CSV or PDF for saving or sharing.
Example Data Table
| Profile | Sex | Age | Weight | Height | Activity | Estimated Maintenance |
|---|---|---|---|---|---|---|
| Office worker | Male | 30 | 70 kg | 175 cm | Moderately active | ~2,556 kcal/day |
| Runner | Female | 27 | 60 kg | 165 cm | Very active | ~2,346 kcal/day |
| Student | Male | 22 | 154 lb | 5 ft 9 in | Lightly active | ~2,268 kcal/day |
| Strength trainee | Female | 35 | 72 kg | 168 cm | Extra active | ~2,781 kcal/day |
FAQs
1. What does maintenance calories mean?
Maintenance calories are the daily calories needed to keep body weight stable. They reflect resting energy use plus movement, training, work activity, and normal digestion.
2. Which formula should I choose?
Mifflin-St Jeor is widely used for general estimates. Harris-Benedict is another classic option. Katch-McArdle is useful when you know body fat because it uses lean body mass.
3. Why does activity level change calories so much?
Activity multipliers scale your resting calorie needs into total daily energy use. Even small changes in weekly movement can noticeably change maintenance calories.
4. Is this result exact?
No calculator is exact for every person. Use the result as a starting point, then watch body weight, performance, hunger, and recovery over two to four weeks.
5. Why include macro targets?
Macros turn calories into usable meal planning targets. Protein supports recovery, carbohydrates support training and energy, and fats support hormones and general health.
6. Should I enter body fat percentage?
Enter body fat only if you have a reasonably reliable estimate. It enables Katch-McArdle, but inaccurate body fat can reduce the quality of the result.
7. Can I use this for weight loss or weight gain?
Yes. First calculate maintenance calories, then reduce calories for fat loss or add calories for weight gain. Small, consistent adjustments usually work best.
8. Why is BMI shown too?
BMI gives a quick body-size reference from weight and height. It does not measure muscle directly, but it adds extra context beside calorie estimates.