Nutrition Tool

Calorie Calculator - Daily Calorie Calculator & BMR Calculator

Free calorie calculator to estimate the number of calories a person needs to consume each day. This calculator can also provide simple guidelines for gaining or losing weight. Calculate BMR using Mifflin-St Jeor, Harris-Benedict, or Katch-McArdle equations.

Last updated: February 2, 2026

Three BMR calculation equations
Calorie needs for maintain, lose, or gain weight
US, Metric, and Other unit support

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Calorie Calculator
Estimate the number of calories you need to consume each day

Ages: 15 - 80

cm
kg

Exercise: 15-30 min elevated heart rate. Intense: 45-120 min. Very intense: 2+ hours.

Calorie Results

BMR (Basal Metabolic Rate)

1,655 Calories/day

Daily calorie needs based on activity level

Maintain Weight2,565 cal
Lose Weight (1 lb/week)2,065 cal
Gain Weight (1 lb/week)3,065 cal

Calorie Guidelines:

  • • 1 pound ≈ 3,500 calories
  • • To lose 1 lb/week: reduce 500 cal/day
  • • Don't reduce more than 1,000 cal/day
  • • Minimum: 1,200 cal (women), 1,500 cal (men)

BMR Calculation Equations

Mifflin-St Jeor Equation
Most accurate equation (introduced 1990)

For Men:

BMR = 10W + 6.25H - 5A + 5

For Women:

BMR = 10W + 6.25H - 5A - 161

W = weight (kg), H = height (cm), A = age

Revised Harris-Benedict
Early equation (revised 1984)

For Men:

BMR = 13.397W + 4.799H - 5.677A + 88.362

For Women:

BMR = 9.247W + 3.098H - 4.330A + 447.593

W = weight (kg), H = height (cm), A = age

Katch-McArdle Formula
Accounts for lean body mass

Formula:

BMR = 370 + 21.6(1 - F)W

W = weight (kg), F = body fat %

More accurate for leaner individuals who know their body fat percentage.

Quick Example Result

For a 25-year-old male with height 180 cm, weight 65 kg, moderate activity:

BMR

1,605 cal/day

Maintain Weight

2,488 cal/day

Lose Weight

1,988 cal/day

How the Calorie Calculator Works

The Calorie Calculator is based on several equations to estimate your Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE). The calculator uses the Mifflin-St Jeor Equation (most accurate), Revised Harris-Benedict Equation, or Katch-McArdle Formula to calculate BMR, then multiplies it by an activity factor to determine your daily calorie needs.

Weight Loss Guidelines

1 pound ≈ 3,500 caloriesBasic conversion
Lose 1 lb/weekReduce 500 cal/day
Maximum safe reduction1,000 cal/day (2 lbs/week)

It's inadvisable to lower calorie intake by more than 1,000 calories per day, as losing more than 2 pounds per week can be unhealthy and may reduce metabolism. Excessive weight loss can also involve muscle loss, which lowers BMR.

Calorie Counting for Weight Loss

Calorie counting can be broken down into a few general steps:

  1. Determine your BMR using one of the provided equations. If you know your body fat percentage, the Katch-McArdle Formula might be more accurate.
  2. Determine your weight loss goals. Recall that 1 pound (~0.45 kg) equates to approximately 3,500 calories. Reducing daily caloric intake by 500 calories per day will theoretically result in a loss of 1 pound a week.
  3. Choose a method to track your calories and progress towards your goals. Smartphone apps, websites, or manual journals can help track calories, exercise, and progress.
  4. Track your progress over time and make changes to better achieve your goals if necessary. Remember that weight loss alone is not the sole determinant of health and fitness.

Zigzag Calorie Cycling

Zigzag calorie cycling is a weight loss approach that aims to counteract the human body's natural adaptive tendencies. It involves alternating the number of calories consumed on a given day. A person on a zigzag diet should have a combination of high-calorie and low-calorie days to meet the same overall weekly calorie target.

For example, if your target calorie intake is 14,000 calories per week, you could consume 2,300 calories three days a week, and 1,775 the other four days of the week, or you could consume 2,000 calories each day. In both cases, 14,000 calories would be consumed over the week, but the body wouldn't adapt and compensate for a constant 2,000-calorie diet.

How Many Calories Do You Need?

The number of calories a person needs depends on age, weight, height, sex, levels of physical activity, and overall general health. Adult males generally require 2,000-3,000 calories per day to maintain weight while adult females need around 1,600-2,400 according to the U.S. Department of Health.

The body does not require many calories to simply survive. However, consuming too few calories results in the body functioning poorly. Harvard Health Publications suggests women get at least 1,200 calories and men get at least 1,500 calories a day unless supervised by doctors.

Food Energy Converter

Convert between Calories and other common food energy units:

1 Calorie [Nutritional, kcal] = 4.1868 Kilojoules [kJ]

Sources & References

  • Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO. - A new predictive equation for resting energy expenditure in healthy individualsAmerican Journal of Clinical Nutrition, 1990
  • Roza AM, Shizgal HM. - The Harris Benedict equation reevaluated: resting energy requirements and the body cell massAmerican Journal of Clinical Nutrition, 1984
  • U.S. Department of Health - Dietary Guidelines for AmericansRecommended daily calorie intake for adults
  • Harvard Health Publications - Minimum Calorie RequirementsWomen: 1,200 cal/day, Men: 1,500 cal/day minimum

Need help with other health calculations? Check out our BMI calculator and body fat calculator.

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Calorie Calculator Examples

Example Calculation
Calculate daily calorie needs for a 25-year-old male using Mifflin-St Jeor Equation

Input Values:

  • Age: 25 years
  • Gender: Male
  • Height: 180 cm
  • Weight: 65 kg
  • Activity: Moderate (4-5 times/week)
  • Equation: Mifflin-St Jeor

Calculation Steps:

  1. Calculate BMR: 10(65) + 6.25(180) - 5(25) + 5 = 1,605
  2. Apply activity multiplier: 1,605 × 1.55 = 2,488
  3. Maintain weight: 2,488 calories/day
  4. Lose weight (1 lb/week): 2,488 - 500 = 1,988 calories/day
  5. Gain weight (1 lb/week): 2,488 + 500 = 2,988 calories/day

Result: BMR = 1,605 cal/day | TDEE = 2,488 cal/day

To lose 1 lb/week: 1,988 cal/day | To gain 1 lb/week: 2,988 cal/day

Female Example

30-year-old female, 165 cm, 60 kg, moderate activity

BMR: ~1,300 cal | TDEE: ~2,015 cal

Weight Loss Example

To lose 1 pound per week

Reduce daily intake by 500 calories

Frequently Asked Questions

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