Enter your details
Choose metric or imperial inputs. Then compare formulas and macro targets for a more complete maintenance estimate.
Formula used
Main equation: Maintenance calories = BMR × activity multiplier + average daily exercise calories + optional thermic adjustment.
Mifflin-St Jeor: Men use 10W + 6.25H - 5A + 5. Women use 10W + 6.25H - 5A - 161.
Other options: Revised Harris-Benedict uses sex, weight, height, and age. Katch-McArdle and Cunningham use lean body mass.
W means weight in kilograms. H means height in centimeters. A means age in years.
How to use this calculator
- Select the unit system that matches your measurements.
- Enter age, sex, height, and current weight.
- Add body fat percentage when using lean mass formulas.
- Pick the activity level that best matches normal weeks.
- Add extra weekly exercise calories only when they are not included.
- Choose macro targets and press the calculate button.
- Track body weight for two weeks, then adjust slowly.
Example data table
| Person | Inputs | Formula | Activity | Estimated maintenance |
|---|---|---|---|---|
| Office worker | 30 years, 75 kg, 175 cm | Mifflin-St Jeor | Moderate | About 2,550 calories/day |
| Light activity | 42 years, 68 kg, 165 cm | Revised Harris-Benedict | Light | About 2,000 calories/day |
| Lean mass known | 28 years, 82 kg, 15% body fat | Katch-McArdle | Active | About 3,050 calories/day |
Examples are rounded. Your real intake can differ because movement, digestion, and tracking accuracy vary.
Understanding maintenance calories
Maintaining weight means matching energy intake with energy use. Your body spends energy all day. It powers breathing, heartbeat, temperature control, digestion, movement, and training. A maintenance calorie target gives a starting point. It is not a fixed law. It is a practical estimate that improves with tracking.
Why BMR matters
Basal metabolic rate is the largest part of daily energy use for many people. It estimates calories burned at complete rest. BMR changes with body size, age, sex, and lean mass. Taller and heavier people usually need more calories. People with more muscle also use more energy. This is why body fat input can help when using lean mass formulas.
Activity changes the final number
Activity multipliers convert resting needs into daily needs. This step includes walking, chores, work, and planned exercise. The multiplier should match a normal week, not your best week. Many people choose a level that is too high. That can make maintenance calories look inflated. When in doubt, pick the lower level first.
Use a range, not one rigid number
Scale weight can move from water, salt, food volume, and hormones. A five percent range is often more useful than a single target. If your estimate is 2,400 calories, a range near 2,280 to 2,520 may still maintain weight. Watch the weekly average. Do not react to one daily weigh-in.
Macros give structure
Protein supports muscle repair and fullness. Fat supports hormones and helps meals taste better. Carbohydrates fuel hard training and busy days. This calculator assigns protein first, then fat, then carbohydrates. You can adjust these values to fit food preference, training style, and comfort.
How to refine the estimate
Eat near the calculated number for fourteen days. Weigh at the same time each morning. Average the readings each week. If weight rises, reduce intake by 100 to 150 calories. If weight falls, add 100 to 150 calories. Small changes work better than large swings. They protect energy, mood, and consistency.
Tracking best practices
Use a food log for the first phase. Measure calorie dense foods when possible. Oils, nuts, sauces, drinks, and snacks can change totals fast. Keep meals repeatable. It also makes adjustments easier. Step count is useful. A steady step average improves the activity estimate.
Energy balance in real life
Maintenance is not the same every day. Sleep, temperature, menstrual cycle changes, job demands, and training load can shift needs. Travel can change food volume and water retention. A flexible target helps you stay calm. Focus on the trend. Let days of data guide change.
When to be careful
This tool is for general planning. It cannot diagnose health issues. Athletes, pregnant people, teens, older adults, and people with medical conditions may need personal guidance. Food logging also has errors. Treat the result as a smart starting estimate. Real feedback should guide the final target.
Frequently asked questions
What are maintenance calories?
Maintenance calories are the calories you need to keep weight stable. They include resting metabolism, daily movement, exercise, and digestion. Eating near this level should keep your weekly average weight close to the same.
Which formula should I choose?
Mifflin-St Jeor is a strong default for many adults. Revised Harris-Benedict is useful for comparison. Katch-McArdle and Cunningham can help when body fat percentage is known and reasonably accurate.
Why does activity level matter so much?
Activity can change daily energy needs by hundreds of calories. Jobs, steps, training, and chores all count. Choose the level that describes your normal week, not a rare active day.
Should I add extra exercise calories?
Add them only when your activity multiplier does not already include them. If you select an active multiplier and also add all workout calories, your estimate may become too high.
How accurate is this calculator?
It gives an informed estimate, not a guaranteed number. Metabolism, food tracking, water balance, and daily movement vary. Two to four weeks of weight trends can refine the result.
Why is there a maintenance range?
A range is useful because body weight changes daily from water, sodium, meals, and digestion. A weekly average gives better feedback than one morning weight reading.
Can I use this while gaining muscle?
Yes. Maintenance calories can support recomp for some people, especially beginners. Advanced lifters may need a small surplus. Training quality, protein intake, and sleep also matter.
How often should I recalculate?
Recalculate after major weight changes, activity changes, or training changes. Many people review the estimate every four to eight weeks, then adjust based on weight trends.
What protein target should I use?
A common planning range is 1.6 to 2.2 grams per kilogram for active adults. Lower targets may fit general wellness. Higher targets may fit dieting or intense training.
Do calories need to match every day?
No. Weekly average intake matters more for maintenance. Some days can be higher and others lower. Keep the weekly total close to your target.
Is this calculator medical advice?
No. It is a planning tool for general education. People with medical conditions, pregnancy, eating disorder history, or special nutrition needs should ask a qualified professional.
Important note
Use this calculator as a planning guide. For health conditions, medication changes, pregnancy, or clinical nutrition needs, seek professional advice.