Maintenance Calorie Calculator

A maintenance calorie calculator tells you how many calories per day keep your weight exactly where it is. It multiplies your resting metabolism by an activity factor. Example: a 35-year-old woman, 5 ft 5 in and 150 lb, who trains three to five days a week maintains on about 2,133 calories per day.

Two sister tools cover the neighboring questions. The TDEE Calculator gives the same maintenance number and then adds ready-made cut and bulk targets, and the Calorie Calculator goes a step further and lays out a full weight-loss or weight-gain calorie plan with a timeline. Use this page when the question is simply "what is my maintenance?", when you want to compare the two classic formulas, or when you want to see how your number moves with weight, age and activity.

How maintenance calories are calculated

The calculator works in two steps. First it estimates your basal metabolic rate (BMR), the energy your body burns at complete rest, with the Mifflin-St Jeor equation:

where s is +5 for men and −161 for women. US inputs are converted first: 1 lb = 0.45359237 kg and 1 in = 2.54 cm. Second, the BMR is multiplied by an activity factor that accounts for everything you do beyond lying still:

The five standard factors are 1.2 (sedentary), 1.375 (lightly active), 1.55 (moderately active), 1.725 (very active) and 1.9 (extra active). For comparison the calculator also runs the revised Harris-Benedict equation (men: 88.362 + 13.397 × kg + 4.799 × cm − 5.677 × age; women: 447.593 + 9.247 × kg + 3.098 × cm − 4.330 × age) through the same multiplier, so you can see how much the choice of formula moves the answer.

Worked example: a 150 lb woman, moderately active

Take the default profile: female, 35 years old, 5 ft 5 in, 150 lb, moderate exercise three to five days a week.

1. Convert units: 150 lb × 0.45359237 = 68.04 kg; 65 in × 2.54 = 165.10 cm.
2. Weight term: 10 × 68.04 = 680.39.
3. Height term: 6.25 × 165.10 = 1,031.88.
4. Age term: 5 × 35 = 175.
5. BMR: 680.39 + 1,031.88 − 175 − 161 = 1,376.3 calories at rest.
6. Maintenance: 1,376.3 × 1.55 = 2,133 calories per day, or about 14,932 calories per week.

The revised Harris-Benedict equation gives a BMR of 1,436.7 calories for the same woman and a maintenance level of about 2,227 calories, 94 calories higher. Both numbers sit inside the plus or minus 10 percent band the calculator shows (roughly 1,920 to 2,347 calories), which is a realistic picture of how precise any formula can be.

Maintenance calories by activity level

The activity factor is the biggest single lever in the calculation. Here is the same 35-year-old woman at every level, under both equations:

From sedentary to extra active the maintenance level rises by 963 calories, a 58 percent jump, while the formula choice only moves it by 72 to 115 calories. Picking the right activity row matters far more than which equation you trust.

Maintenance calories by body weight

Heavier bodies burn more at rest and in motion. The table shows Mifflin-St Jeor maintenance calories at age 35 for a woman of 5 ft 4 in and a man of 5 ft 10 in, both sedentary (1.2) and moderately active (1.55):

Each 20 lb step adds about 109 calories of sedentary maintenance and about 140 calories at the moderate level, for both sexes, because the weight term in the equation is the same 10 calories per kilogram regardless of sex. The gap between the man and the woman at equal weight (roughly 314 sedentary, 405 moderate) comes from his extra 6 inches of height and the +5 versus −161 constant.

Maintenance calories by age

Age enters the equation as a steady 5-calorie drop in BMR per year. For the two example profiles at a moderate (1.55) activity level:

A decade costs about 50 calories of BMR and 78 calories of maintenance at the moderate level. In real life the decline is often steeper because people also lose muscle and move less as they age, neither of which the equation sees.

A second worked example: a 200 lb man, lightly active

Male, 42 years old, 5 ft 11 in, 200 lb, light exercise one to three days a week. Converted, that is 90.72 kg and 180.34 cm. The weight term is 10 × 90.72 = 907.18, the height term 6.25 × 180.34 = 1,127.12, and the age term 5 × 42 = 210. BMR = 907.18 + 1,127.12 − 210 + 5 = 1,829.3 calories. With the lightly active factor, maintenance = 1,829.3 × 1.375 = 2,515 calories per day. Harris-Benedict puts his BMR at 1,930.7 and his maintenance at about 2,655 calories, 140 higher. If this man bumped his training to three to five days a week, the moderate factor would lift his maintenance to about 2,835 calories, an extra 320 calories of food each day just from the activity change.

Why the two formulas disagree

The original Harris-Benedict equation dates from 1919 and was revised in 1984; Mifflin-St Jeor was fitted in 1990 to a larger group of modern adults, including more overweight participants. Harris-Benedict weights body mass more heavily (13.397 versus 10 calories per kilogram for men), so its estimate climbs faster as weight rises. Across the profiles used on this page the Harris-Benedict maintenance figure runs 72 to roughly 205 calories above Mifflin-St Jeor, with the widest gap for heavier, older men: for a 60-year-old man at 6 ft and 230 lb it gives 3,136 calories against 2,931. Because the Mifflin-St Jeor sample is closer to today's population, its number is the headline result here, and the Harris-Benedict value is best read as the upper edge of a plausible range.

Using your maintenance number: hold, cut or bulk

Maintenance is the anchor for every calorie plan. To hold your weight, eat the headline number and check the scale weekly. To lose fat at a sustainable pace, subtract 250 to 500 calories: for the example woman that is 1,883 or 1,633 calories per day, aiming for roughly half a pound to one pound per week, since a pound of stored fat represents about 3,500 calories. To gain muscle with limited fat, add 250 to 300 calories, which puts her at about 2,433, and pair the surplus with resistance training. Whatever direction you choose, the plan only works if the anchor is right, which is why it pays to confirm maintenance with two or three weeks of tracking before adding a deficit or surplus on top.

How to use this calculator

1. Pick your units: US (lb, ft/in) is the default; switch to metric (kg, cm) if you prefer.
2. Select your sex so the right constant (+5 or −161) is applied.
3. Enter age, weight and height. Use your actual morning weight, not a goal weight.
4. Choose an activity level that matches your whole week, including your job and your walking, not just your workouts.
5. Read the headline number: your Mifflin-St Jeor maintenance calories per day, with BMR, the weekly total, the Harris-Benedict cross-check and a plus or minus 10 percent range underneath.
6. Scan the tables to see what every activity level would give you and how your number shifts if your weight goes up or down.

The result updates instantly with every change, so you can test how a different activity level or a 10 lb change moves your maintenance before committing to a plan.

Who this calculator is for

• People finishing a diet who need to know where to land their intake so the weight stays off.
• Lifters between phases who want to hold weight at maintenance for a few weeks before the next cut or bulk.
• Anyone tracking food who needs a starting daily budget for their app.
• Runners and athletes checking whether their intake keeps up with a heavy training week.
• Curious readers who want to understand why two people of the same weight need different amounts of food.

Key terms explained

• Maintenance calories: the daily intake at which weight is stable; energy in equals energy out.
• BMR (basal metabolic rate): calories burned at complete rest to keep organs running. Typically 60 to 70 percent of a sedentary person's total burn.
• TDEE (total daily energy expenditure): BMR plus digestion, daily movement and exercise. Numerically the same as maintenance calories.
• Activity factor: the multiplier (1.2 to 1.9) that turns BMR into TDEE.
• NEAT: non-exercise activity thermogenesis, the calories from fidgeting, walking, chores and standing. It is the main reason two people with the same workouts have different maintenance levels.
• Thermic effect of food: the roughly 10 percent of intake spent digesting and processing it; the activity factor includes it.
• Energy balance: the difference between calories eaten and calories burned. A sustained surplus becomes stored weight, a sustained deficit draws it down.

What changes your maintenance calories the most

• Activity level: from 1.2 to 1.9 the factor changes maintenance by 58 percent. It is the largest lever by far.
• Body weight: about 45 calories of BMR per 10 lb, or 70 calories of maintenance at the moderate level.
• Height: each extra inch adds 6.25 × 2.54 = 15.9 calories of BMR.
• Age: 5 calories of BMR per year, or roughly 78 calories of maintenance per decade at the moderate level.
• Sex: the constant differs by 166 calories, and men are usually taller and carry more muscle, widening the gap.
• Muscle mass: not in the formula, but lean tissue burns more than fat, so a muscular person at the same weight maintains on more.

Tips for finding your true maintenance

• Start at the estimate, then measure. Eat the number for two to three weeks, weigh yourself every morning, and compare weekly averages.
• Adjust in small steps. If the weekly average moves, change intake by 100 to 200 calories, not 500, and wait another two weeks.
• Be honest about activity. When in doubt, choose the lower factor; it is easier to add food than to explain unexpected gain.
• Recalculate after change. A 10 to 15 lb swing, a new job or a new training schedule all shift the number.
• Use the range, not the point. The plus or minus 10 percent band is the honest answer; the single number is just its center.

Limitations and assumptions

• Both equations were derived from healthy adults; they are less reliable for children, pregnant women, people with very high or very low body fat, and anyone with a thyroid or metabolic condition.
• The activity factors are broad categories. Real daily movement varies from day to day and person to person.
• Neither formula knows your body composition. Two people with the same height, weight, age and sex get the same number even if one has far more muscle.
• Metabolic adaptation after long dieting can lower actual expenditure below the estimate for a while.
• Food-label calories carry legal tolerances, so your logged intake is itself an estimate.

Related calculators

If your goal is not to maintain, move one step along the chain. The BMR Calculator isolates the resting number before any activity multiplier. The TDEE Calculator takes this maintenance figure and attaches cut and bulk targets. The Calorie Deficit Calculator turns a chosen deficit into a weight-loss timeline, and the Macro Calculator splits your maintenance calories into protein, carbohydrate and fat grams.

Sources

• National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) - Body Weight Planner (energy balance and maintenance intake).
• National Institutes of Health (NIH), NHLBI - Balance Food and Activity.
• Mifflin MD, St Jeor ST, et al. (1990). A new predictive equation for resting energy expenditure in healthy individuals. American Journal of Clinical Nutrition, 51(2), 241-247.
• Roza AM, Shizgal HM (1984). The Harris Benedict equation reevaluated. American Journal of Clinical Nutrition, 40(1), 168-182.