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Daily Calorie Calculator

HealthMacros and Calories
About you
Units
Sex
Activity
Calories to maintain weight —
Resting metabolic rate (kcal)
—
Mild loss, −250 kcal
—
Weight loss, −500 kcal
—
Weight gain, +500 kcal
—

Daily calorie needs are estimated by working out resting metabolic rate with the Mifflin-St Jeor equation and multiplying it by an activity factor from 1.2 to 1.9. A 30-year-old man at 175 cm and 70 kg burns about 1,649 kcal at rest and roughly 2,556 kcal a day with moderate exercise.

About this tool

People planning meals, starting a cut or bulking for sport all need a starting number for how much energy their body uses in a day. This calculator applies the Mifflin-St Jeor equation, which dietitians widely use for healthy adults, to your age, sex, height and weight, then scales it by how active you are. It returns maintenance calories, the resting figure behind them, and three adjusted targets: a 250 kcal and a 500 kcal deficit and a 500 kcal surplus. The working shows each multiplication. Treat the answer as an estimate within about 10 percent for most people; track your weight for two to three weeks and adjust from there.

How to use it

  1. Pick units and sex

    Choose metric or US units, then female or male, which changes the equation's constant.

  2. Enter age, height and weight

    Use the stepper for age; height and weight fields follow the units you picked.

  3. Choose an activity level

    Select the description closest to an average week, counting both job and exercise.

  4. Read the targets

    Maintenance appears first, with resting needs and the loss and gain targets below it.

Examples

Man, 30, 175 cm, 70 kg, moderate

Units
Metric (kg, cm)
Sex
Male
Age
30
Height
175
Weight
70
Activity level
Moderate (3–5 days/week)

Result Calories to maintain weight: 2,556
Resting metabolic rate (kcal): 1,649
Mild loss, −250 kcal: 2,306
Weight loss, −500 kcal: 2,056
Weight gain, +500 kcal: 3,056

  1. Weight = 70 kg, height = 175 cm, age = 30
  2. BMR = 10 × 70 + 6.25 × 175 − 5 × 30 + 5 = 1648.8 kcal
  3. Maintenance = 1648.8 × 1.55 (Moderately active) = 2556 kcal/day
  4. Loss ≈ maintenance − 500, gain ≈ maintenance + 500

Resting needs of about 1,649 kcal rise to roughly 2,556 kcal once three to five training days a week are counted.

Woman, 40, 165 cm, 60 kg, light

Units
Metric (kg, cm)
Sex
Female
Age
40
Height
165
Weight
60
Activity level
Light (1–3 days/week)

Result Calories to maintain weight: 1,747
Resting metabolic rate (kcal): 1,270
Mild loss, −250 kcal: 1,497
Weight loss, −500 kcal: 1,247
Weight gain, +500 kcal: 2,247

  1. Weight = 60 kg, height = 165 cm, age = 40
  2. BMR = 10 × 60 + 6.25 × 165 − 5 × 40 − 161 = 1270.3 kcal
  3. Maintenance = 1270.3 × 1.375 (Lightly active) = 1747 kcal/day
  4. Loss ≈ maintenance − 500, gain ≈ maintenance + 500

The female equation subtracts 161 instead of adding 5, so the same build needs fewer calories than a man's would.

Woman, 60, 155 cm, 50 kg, sedentary

Units
Metric (kg, cm)
Sex
Female
Age
60
Height
155
Weight
50
Activity level
Sedentary (desk, no exercise)

Result Calories to maintain weight: 1,209
Resting metabolic rate (kcal): 1,008
Mild loss, −250 kcal: 959
Weight loss, −500 kcal: 709
Weight gain, +500 kcal: 1,709

  1. Weight = 50 kg, height = 155 cm, age = 60
  2. BMR = 10 × 50 + 6.25 × 155 − 5 × 60 − 161 = 1007.8 kcal
  3. Maintenance = 1007.8 × 1.2 (Sedentary) = 1209 kcal/day
  4. Loss ≈ maintenance − 500, gain ≈ maintenance + 500

Maintenance is already near 1,200 kcal, so a 500 kcal cut would drop well under that floor and triggers a caution.

How it is calculated

BMR = 10 × W + 6.25 × H − 5 × A + s; daily calories = BMR × activity factor

W
weight in kilograms (pounds × 0.45359237)
H
height in centimetres (inches × 2.54)
A
age in years
s
+5 for men, −161 for women
activity factor
1.2 sedentary, 1.375 light, 1.55 moderate, 1.725 very active, 1.9 extra active

Mifflin and colleagues derived the resting equation in 1990 from measured energy use in 498 healthy adults, and later reviews found it closer to measured values than the older Harris-Benedict formula. Multiplying by the activity factor gives total daily energy expenditure. The loss and gain lines simply subtract or add a fixed number of kilocalories from that maintenance figure.

Sources

When not to use it

  • During pregnancy or breastfeeding, when energy needs follow separate guidance.
  • For children and teenagers, whose growth needs are not covered by this adult equation.
  • For people with very high muscle mass or obesity, where measured resting energy can differ widely from the estimate.

Common mistakes

  • Choosing a higher activity level than an average week supports, which can add several hundred kcal.
  • Counting exercise calories again on top of an activity factor that already includes them.
  • Expecting a 500 kcal deficit to keep producing the same loss as body weight falls.

Frequently asked questions

Why does sex change the result?

At the same height, weight and age, men on average carry more lean mass, which burns more energy at rest. The equation reflects this with a constant: plus 5 for men and minus 161 for women, a gap of 166 kcal before the activity factor is applied.

How does a 500 kcal daily deficit translate into weight loss?

A common rule of thumb is about 0.45 kg (1 lb) a week, but real loss slows over time because a smaller body burns less. NIH's Body Weight Planner models that adaptation if you want a longer projection.

Why is my resting figure lower than I expected?

Resting metabolic rate is the energy for breathing, circulation and organ function while lying still. It is often 60 to 70 percent of total daily needs; the activity factor accounts for the rest.

Is Mifflin-St Jeor better than Harris-Benedict?

Comparisons against measured resting energy in healthy adults generally found Mifflin-St Jeor within 10 percent for more people than Harris-Benedict, which is why many dietitians default to it. Both remain estimates.

Which activity level fits an office worker who runs three times a week?

Usually light or moderate. If runs are 30 minutes at an easy pace, light (1.375) is the closer match; longer or harder sessions move you toward moderate (1.55).

Why does the result fall as I get older?

The equation subtracts 5 kcal for each year of age, reflecting the gradual loss of lean tissue. Ten extra years lowers resting needs by 50 kcal before the activity factor.

Cite this tool

Using this tool in an assignment, article or report? Copy a citation, or a link for your website.

APA

Tools Directory Editorial Team. (2026, October 15). Daily Calorie Calculator. Tools Directory. Retrieved October 25, 2026, from https://tools.milunir.com/health/macros-and-calories/daily-calorie-calculator/

MLA

Tools Directory Editorial Team. “Daily Calorie Calculator.” Tools Directory, 15 Oct. 2026, https://tools.milunir.com/health/macros-and-calories/daily-calorie-calculator/. Accessed 25 Oct. 2026.

Chicago

Tools Directory Editorial Team. “Daily Calorie Calculator.” Tools Directory. Last modified October 15, 2026. Accessed October 25, 2026. https://tools.milunir.com/health/macros-and-calories/daily-calorie-calculator/.

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