Formula Used
Mifflin St Jeor: Men: BMR = 10W + 6.25H - 5A + 5. Women: BMR = 10W + 6.25H - 5A - 161.
Revised Harris Benedict: Men: BMR = 88.362 + 13.397W + 4.799H - 5.677A. Women: BMR = 447.593 + 9.247W + 3.098H - 4.330A.
Katch McArdle: BMR = 370 + 21.6 × lean body mass in kg.
Maintenance: Calories = BMR × activity factor + exercise calories + adjustment. Optional digestion allowance is applied when selected.
How to Use This Calculator
- Enter age, sex, weight, and height.
- Select the matching units for weight and height.
- Choose a formula and activity level.
- Add body fat percentage when using Katch McArdle.
- Add optional exercise calories or daily adjustment.
- Press the calculate button.
- Review calories, range, and macro guide.
- Download CSV or PDF when needed.
Example Data Table
| Person | Age | Weight | Height | Activity | Formula | Estimated Maintenance |
|---|---|---|---|---|---|---|
| Example A | 30 | 70 kg | 175 cm | Moderate | Mifflin St Jeor | About 2550 calories |
| Example B | 42 | 185 lb | 5 ft 10 in | Light | Harris Benedict | About 2460 calories |
| Example C | 26 | 62 kg | 168 cm | Very active | Katch McArdle | About 2600 calories |
Understanding maintenance calories
Maintenance calories are the calories your body needs each day. They keep body weight mostly stable. The value is not a fixed truth. It is a practical estimate. It changes with movement, sleep, stress, training, and body size. This calculator converts common body measurements. It then applies a selected metabolic formula. The result gives a daily intake target for weight maintenance.
Why formulas differ
Each formula estimates basal metabolic rate. Basal metabolic rate is the energy used at rest. Mifflin St Jeor is a common default. Harris Benedict may suit users who compare older diet records. Katch McArdle uses lean body mass. It can help trained users who know body fat percentage. No formula knows your exact metabolism. So the best result is a starting point, not a promise.
Activity and exercise
Activity factors turn resting calories into daily calories. A desk worker needs a lower factor. A runner, builder, or athlete needs a higher factor. The extra exercise field lets you add planned daily workout calories. Use an average, not your highest day. This keeps the result balanced across a week. The digestion option estimates thermic effect of food. Keep it at zero when your activity factor already includes normal digestion.
Using the result
Start with the maintenance estimate for two weeks. Track morning body weight several times per week. Use the average, not one day. If weight rises, reduce intake slightly. If weight falls, add a small amount. A change of 100 to 200 calories is usually enough. Protein, fiber, water, and sleep still matter. Maintenance is easier when meals are consistent. It is also easier when activity is predictable.
Practical planning
Use the lower and upper range as a flexible eating zone. Choose the middle value on normal days. Use the higher side on hard training days. Use the lower side on rest days. Recalculate after weight, activity, or training changes. This makes the calculator useful for long term planning. Food labels, apps, and kitchen scales can improve accuracy. Still, perfection is not required. A steady pattern matters more than one meal. Review progress monthly. Then update inputs, habits, and targets. Small changes are safer and easier to maintain over time for most adults.
FAQs
What are maintenance calories?
Maintenance calories are the daily calories needed to keep body weight stable. They include resting energy, activity, exercise, and normal daily movement.
Which formula should I choose?
Mifflin St Jeor is a strong default for many adults. Katch McArdle is useful when you know your body fat percentage.
Why is body fat optional?
Only Katch McArdle needs body fat. Other formulas use sex, age, height, and weight instead of lean mass.
What activity level should I select?
Choose the level that matches your average week. Do not select your hardest day unless every day is similar.
Should I add exercise calories?
Add them only when your selected activity factor does not already include planned workouts. Use a weekly average for better accuracy.
Why does the calculator show a range?
The range gives flexibility. Real maintenance changes with sleep, stress, movement, digestion, and tracking accuracy.
How often should I recalculate?
Recalculate after a clear weight change, a new training routine, or a major shift in daily activity.
Is this medical advice?
No. It is an estimate for planning. Ask a qualified professional for personal medical or diet treatment.