How many calories should I eat per day?

The average adult needs approximately 2,000 to 2,500 calories per day to maintain their weight, but this varies significantly based on age, sex, height, weight, and activity level. Sedentary women typically need 1,600 to 2,000 calories, active women 2,000 to 2,400, sedentary men 2,000 to 2,400, and active men 2,400 to 3,000. Use this calculator for a personalised estimate.

What is the Mifflin-St Jeor equation?

The Mifflin-St Jeor equation is the most widely recommended formula for estimating Basal Metabolic Rate (BMR). For men: BMR = (10 x weight in kg) + (6.25 x height in cm) - (5 x age) + 5. For women: BMR = (10 x weight in kg) + (6.25 x height in cm) - (5 x age) - 161. This BMR is then multiplied by an activity factor to give your Total Daily Energy Expenditure (TDEE).

How many calories to lose weight?

To lose weight, you need to eat fewer calories than your body burns (a calorie deficit). A deficit of 500 calories per day results in approximately 0.5 kg (1 lb) of weight loss per week. A deficit of 250 calories per day is more moderate at approximately 0.25 kg per week. It is generally recommended not to eat below 1,200 calories per day for women or 1,500 for men without medical supervision.

What are activity level multipliers?

Activity multipliers convert your BMR to total daily calories (TDEE). Sedentary (little or no exercise): BMR x 1.2. Lightly active (light exercise 1-3 days/week): BMR x 1.375. Moderately active (moderate exercise 3-5 days/week): BMR x 1.55. Very active (hard exercise 6-7 days/week): BMR x 1.725. Extra active (very hard exercise, physical job): BMR x 1.9.

How many calories do I need to gain weight?

To gain weight, eat more calories than your body burns (a calorie surplus). A surplus of 250 to 500 calories per day supports a gradual weight gain of 0.25 to 0.5 kg per week. For muscle gain specifically, combine this surplus with resistance training and adequate protein intake (1.6 to 2.2 g per kg of body weight per day).

Calorie Calculator

Find out how many calories you need per day to maintain your weight, lose weight, or gain weight. Enter your details below for a personalised estimate using the Mifflin-St Jeor equation.

Updated April 2026 Mifflin-St Jeor equation (1990). Recommended by the Academy of Nutrition and Dietetics.

1. Your Details

Sex

Age

years

Height

Weight

2. Activity Level

How active are you?

Goal

Your Daily Calorie Needs

BMR

Basal Metabolic Rate

Maintenance

To maintain weight (TDEE)

Your Target
-
Based on your goal

Weekly Change

Estimated weight change

Calorie Targets

BMR (Mifflin-St Jeor)-

Activity multiplier-

Maintenance (TDEE)-

Lose slowly (-250/day)-

Lose (-500/day)-

Lose fast (-1000/day)-

Gain slowly (+250/day)-

Gain (+500/day)-

Macro Estimates (Balanced)

Protein (30%)-

Carbohydrates (40%)-

Fat (30%)-

Protein per kg body weight-

Total daily calories-

Go deeperTDEE Calculator | Deficit Calculator

Result: -

How Calories Are Calculated

This calculator uses the Mifflin-St Jeor equation (1990), which is considered the most accurate formula for estimating Basal Metabolic Rate (BMR) by the Academy of Nutrition and Dietetics. Your BMR is the number of calories your body burns at rest to maintain basic functions like breathing, circulation, and cell production. Your Total Daily Energy Expenditure (TDEE) is your BMR multiplied by an activity factor.

The Mifflin-St Jeor Equation

Men: BMR = (10 x weight in kg) + (6.25 x height in cm) - (5 x age in years) + 5

Women: BMR = (10 x weight in kg) + (6.25 x height in cm) - (5 x age in years) - 161

Activity Level Multipliers

Level	Description	Multiplier
Sedentary	Little or no exercise, desk job	1.2
Lightly active	Light exercise 1-3 days/week	1.375
Moderately active	Moderate exercise 3-5 days/week	1.55
Very active	Hard exercise 6-7 days/week	1.725
Extra active	Very hard exercise, physical job	1.9

Weight Loss and Gain Guidelines

One kilogram of body fat contains approximately 7,700 calories. A daily deficit of 500 calories results in approximately 0.5 kg of weight loss per week (500 x 7 = 3,500 cal = ~0.45 kg). It is generally recommended not to eat below 1,200 calories per day (women) or 1,500 (men) without medical supervision, as this can lead to nutrient deficiencies and metabolic slowdown.

Related Calculators

Sources: Mifflin MD, St Jeor ST, et al. "A new predictive equation for resting energy expenditure in healthy individuals." American Journal of Clinical Nutrition, 1990. Academy of Nutrition and Dietetics evidence analysis library.

This calculator provides estimates based on the Mifflin-St Jeor equation and population-level activity multipliers. Individual calorie needs vary based on genetics, body composition, metabolism, and other factors. Consult a registered dietitian or doctor before making significant changes to your diet, especially if you have a medical condition.