Calories to gain muscle for a 42 kg woman

PeakX · Calorie targets · Updated 2026-11-11

About 2,000 kcal on training days and 1,850 kcal on rest days, with 85 g protein, if you are 26, 158 cm and train 3–5 days a week. Your maintenance is about 1,731 kcal.

How the number is worked out

1. Resting energy (Mifflin-St Jeor): 10 × 42 + 6.25 × 158 − 5 × 26 − 161 = 1,117 kcal.
2. Times 1.55 for moderate activity = 1,731 kcal to stay the same weight.
3. Plus 250 kcal to gain muscle, rounded to 50 = 2,000 kcal. Rest days are 150 kcal lower.
4. Protein at 2 g per kg = 85 g. Fat at 25% of calories = 55 g. Carbs fill the rest: 290 g.

By how active you are

By age (moderately active)

Height matters too: every 5 cm taller adds about 31 kcal to resting energy, or about 50 kcal a day at moderate activity.

What to expect

A 250 kcal surplus with hard training adds roughly 0.2–0.3 kg a week, a pace that keeps most of the gain as muscle. If your waist grows faster than your lifts, drop 100–150 kcal.

A vegetarian Indian day at this target

This day lands at 2,042 kcal and 120 g protein. Most of the protein comes from whey shake (with water) (48 g), roti (17 g), paneer bhurji (15 g).