Free calorie & macro calculator
Give your goal
a daily target.
A few details. A calorie target. Something you can actually work toward.
Weight gain · 18+ · cm & kg
- 01 Your body
- 02 Your goal
- 03 Your targets
First, your starting point.
How this estimate works
Where do the calories come from?
The Mifflin-St Jeor formula estimates resting energy from age, height, weight and a sex-specific constant. We multiply that by an activity factor: low 1.4, moderate 1.55 or high 1.7. Your chosen weekly gain adds a daily surplus using 7,700 kcal per kg, divided by seven days.
How are macros calculated?
Protein starts at 1.8 g per kg of current weight, fat at 0.9 g per kg, both rounded to whole grams. Carbs use the remaining calories, floored at zero. Calories round to the nearest ten. Gram rounding can cause small differences. If protein and fat already exceed the calorie target, the result flags that larger mismatch; it is not just rounding, and those defaults are not a balanced plan.
Does a higher goal mean eating more?
Not on its own. Your current body data, activity and chosen weekly pace determine daily calories. The difference between target and current weight, divided by pace, determines the estimated duration. This is a static estimate, not a promised date or a prediction of muscle gain.
Which sex constant is used?
The formula defines male and female constants. Selecting Other uses the female constant, the lower estimate, matching UBulk. This is a formula fallback, not an individualized assessment.
Who is this for?
Adults aged 18–100 planning to gain weight. Inputs use cm and kg. Supported weights are 40–250 kg and heights 120–230 cm; supported ranges are not recommended goals. If you are underweight, have unexplained weight loss or a medical condition, speak with a qualified clinician before following a calorie target.
What should I do next?
Use the result as a starting estimate and review it against your actual weight trend. Weight gain includes more than muscle. Build a starting workout split if you need a training week.