Calorie Calculator – Calculate Your Daily Needs

This calculation uses the Mifflin–St Jeor equation and provides an estimate for adults. Individual needs can vary. It is not medical advice.

How many calories should I eat a day?

There is no single daily calorie number that fits everyone. Your maintenance calories are the estimated amount you could eat each day to roughly match the calories your body uses and keep your weight stable over time. This calorie calculator uses your body details and usual activity to calculate a starting maintenance target, plus lower and higher examples for different goals.

Your daily calorie needs can shift as your body weight, activity or circumstances change. That is why a calculator result works best as a guide you can review, rather than a fixed prescription.

How to calculate daily calorie needs

Age, sex, height, weight and activity level all affect daily calorie needs. The calculator first estimates energy use at rest, then accounts for usual activity.

There is no single daily calorie target for a woman or a man. The Female or Male option changes one constant in the equation, while the other inputs still shape the result. Two women or two men can therefore have different daily calorie needs.

BMR: The Mifflin-St Jeor equation estimates energy use at rest: 10 × weight (kg) + 6.25 × height (cm) − 5 × age (years), then + 5 for Male or − 161 for Female. The calculator labels this estimate BMR.
Maintenance calories: Multiply BMR by the activity factor for your chosen level. This estimates your total daily energy expenditure (TDEE), or the calories you use in a day. To maintain weight, you would start by eating about the same number of calories. The calculator shows that intake as maintenance calories.
Goal examples: For a weight-loss example, the calculator subtracts 300 Cal from maintenance but never displays less than estimated BMR. For weight gain, it adds 300 Cal. These goal examples illustrate a direction, not a promised rate of weight change.

BMR, TDEE and maintenance calories explained

These terms answer three different questions: How much energy does your body use at rest? How much does it use in a typical day? And how much might you eat to match that daily use?

Estimated energy at rest
BMR: Basal metabolic rate refers to energy used for basic functions at rest. Here, BMR is an estimate from a resting energy expenditure equation, not a direct measurement. It does not include a full day's activity.
Estimated daily energy use
TDEE: Total daily energy expenditure includes the energy your body uses at rest, during daily movement and exercise, and while digesting food. TDEE describes calories used over a day, not calories eaten.
Estimated intake for stable weight
Maintenance calories: Maintenance calories estimate how much you could eat each day to balance TDEE and keep your weight roughly stable. In this calculator, TDEE and maintenance calories have the same estimated value: one describes energy used; the other, the matching intake.

A worked example

A 35-year-old woman who is 164 cm (about 5 ft 5 in) tall and weighs 70 kg (about 154 lb) selects Female and Moderately active (activity factor 1.55).

BMR: 10 × 70 + 6.25 × 164 − 5 × 35 − 161 = 1,389 Cal/day.
TDEE: 1,389 × 1.55 ≈ 2,153 Cal/day.
Maintenance calories: about 2,153 Cal/day. This is the same estimated number, now expressed as an intake that could balance daily energy use.

The calculator also shows about 1,853 Cal/day as a weight loss example and 2,453 Cal/day as a weight gain example. These are starting points, not fixed recommendations.

Your intake can vary from day to day; the longer-term average matters more. Your actual maintenance level may differ from the TDEE estimate.

How the calculator uses activity level

Choose the activity level closest to your usual week, including work, walking and exercise. One unusually active day is not a good guide to your daily calorie needs.

Physical Activity Level (PAL) describes the ratio of daily energy use to energy use at rest. The activity factors below are fixed calculator presets, not measurements of your personal PAL or official activity categories.

Activity levelFactorTypical week

Activity levelMostly seated

Factor1.2

Seated work and little walking, with little or no planned exercise.

Activity levelLightly active

Factor1.375

Mostly seated days, with regular walks or occasional light exercise.

Activity levelModerately active

Factor1.55

Regular walking or active daily routines, plus exercise on several days.

Activity levelVery active

Factor1.725

Active days on your feet or frequent demanding workouts, with substantial movement outside training.

Activity levelExtremely active

Factor1.9

Physically demanding days combined with frequent training, or similarly high activity across the week.

These descriptions are guides, not strict cutoffs. If your job, walking or training changes substantially, select the level that fits your new routine and recalculate.

Using your calculated calorie target for different goals

Your calculated maintenance calories are the starting point. The calculator shows simple examples for weight loss, maintaining weight and weight gain.

GoalCalculator example

Weight loss≈ maintenance − 300 Cal

Maintain weight≈ maintenance

Gain weight≈ maintenance + 300 Cal

The ±300 Cal values are simple calculator examples, not individualized recommendations. Your body weight can fluctuate from day to day even when your average intake is consistent. Compare its trend with your goal before changing your intake, and recalculate if your weight or routine changes meaningfully. If weight loss is your goal and you want a dedicated target below maintenance, use the Macroful Calorie Deficit Calculator.

Want to turn your calorie target into daily protein, carb and fat targets? Use the Macro Calculator.

To compare that target with the meals you actually eat, use Macroful’s photo calorie counter to log a meal from a photo.

How accurate is a calorie calculator?

A calorie calculator gives an estimate, not a direct measurement of your energy needs. The Mifflin-St Jeor equation predicts resting energy use from population data. People with the same inputs can still have different energy needs. The selected activity factor adds another approximation. Other calculators may show different numbers because they use different formulas, activity factors or rounding.

Compare the result with your logged intake and weight trend over several weeks, rather than one day's reading. Maintenance calories can change as weight and activity change. For pregnancy, breastfeeding or a medical condition that affects nutrition, ask a qualified health professional for individual guidance.

Formula source: original Mifflin-St Jeor study.

Frequently asked questions about calorie needs

How many calories does a woman need per day?

There is no single calorie target that applies to every woman. As a broad reference, U.S. Dietary Guidelines tables have estimated adult women's maintenance needs at roughly 1,600 to 2,400 calories per day, depending mainly on age and activity. Height, weight and body composition can shift an individual's needs further. Use the calculator to estimate your own maintenance calories rather than treating this range as a personal target. Pregnancy and breastfeeding require separate considerations.

How many calories does a man need per day?

There is no single calorie target that applies to every man. As a broad reference, U.S. Dietary Guidelines tables have estimated adult men's maintenance needs at roughly 2,000 to 3,000 calories per day, depending mainly on age and activity. Height, weight and body composition can shift an individual's needs further. Use the calculator to estimate your own maintenance calories and compare the result with your weight trend over time.

How many calories do I burn in a day?

Your total daily energy expenditure (TDEE) includes energy used at rest, during everyday movement and exercise, and while digesting food. The calculator estimates it from BMR and your selected activity factor. It represents a typical day, not a measurement of any one day.

What are maintenance calories, and how do they relate to TDEE?

Maintenance calories are an estimated daily intake that could roughly balance your TDEE. The calculator shows the same number for both: TDEE describes calories used, while maintenance calories describe an intake that might match that use. Your weight trend over several weeks helps you judge whether the estimate fits you.

Which activity level should I choose if my days vary?

Choose the level that best represents your usual week, including work, walking and exercise. Do not base it on one unusually active day. Your regular workouts are already reflected in the activity factor, so do not add those exercise calories again. Recalculate if your routine changes substantially.

Can I use this calculator if I am under 18?

No. The form accepts ages 18 to 100, and the result is intended for adults. It does not provide a calorie target for children or teens.

Is my BMR the minimum number of calories I should eat?

No. BMR describes estimated energy use at rest, not a personal minimum intake or a recommended diet target. The calculator uses it only as a limit on its simple weight loss example.

From target to daily tracking

You’ve got your calorie target. Now put it to work.

Log meals with Macroful using a photo, barcode scan or food search. See how your daily intake compares with your target.

Macroful

Snap your meal. See calories and macros at a glance.