Free tool
Calorie and macro calculator
Work out how many calories you need a day to maintain, lose or gain weight, and how to split protein, fat and carbs. It's an estimate using the Mifflin-St Jeor equation, one of the most widely used and accurate for adults.
Not for pregnancy, eating disorders or medical conditions: in those cases, check with a professional.
Gojan builds the routine and changes it when you tell it your week falls apart.
How it's calculated
First, your basal metabolic rate (BMR) with Mifflin-St Jeor: 10 × weight (kg) + 6.25 × height (cm) − 5 × age, + 5 for men or − 161 for women. Then it's multiplied by your activity level: 1.2 sedentary, 1.375 light, 1.55 moderate, 1.725 high and 1.9 very high. The result is your maintenance. To lose weight, subtract 10 to 25%; to build muscle, add 5 to 10%. Protein runs from 1.6 to 2.2 g per kilo of body weight: a 2018 meta-analysis (Morton and colleagues, British Journal of Sports Medicine) found that, in people who lift weights, extra muscle gain is minimal above about 1.6 g/kg, and 2.2 g/kg is the upper end of its estimate. If your body mass index is above 25, protein is calculated on the weight that would give a 25, so the number isn't inflated. Fat runs from 20 to 35% of calories, the range recommended for adults by the US Institute of Medicine (2005), and each gram provides 9 kcal. Protein provides 4 kcal per gram, and carbs make up the rest, also at 4 kcal per gram.
Frequently asked questions
How accurate is it?
It's an estimate: for most adults Mifflin-St Jeor lands close to actual expenditure, but everyone is different. Use it as a starting point and adjust based on how your weight changes over two or three weeks.
How many calories should I eat to lose weight?
10 to 25% below your maintenance. A moderate deficit is easier to sustain and helps protect muscle, especially if you lift weights and eat enough protein.
And to build muscle?
5 to 10% above your maintenance, together with strength training. Going beyond that adds little extra muscle and more fat.
Why does it ask for my sex?
Because the equation uses a different adjustment for men and women (+5 or −161), reflecting average differences in body composition.
What are macros?
The three nutrients that provide calories: protein and carbs, at 4 kcal per gram, and fat, at 9.
How should I split macros to lose weight?
Keep protein in the range the calculator gives you, which helps protect muscle in a deficit, and cut mostly carbs and fat, without taking fat below 20% of your calories.