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Weight Gain Calculator

Gaining weight healthily means eating a little more than you burn, every day, while building muscle rather than just fat. This calculator works out your maintenance calories, adds the surplus you choose, and checks your BMI first.

This calculator is for adults (18+). Children and teenagers who need to gain weight should be assessed against growth charts — ask us.
Your BMI is already above the healthy range for Indians. Gaining more weight may not be right for you — if you want to build muscle, talk to us so the plan adds muscle rather than fat.

BMI

Indian cut-off (healthy 18–22.9)

Calories per day

Formula Maintenance To gain
Mifflin-St Jeor
MET

Maintenance = BMR × ; to gain = maintenance + kcal. Mifflin-St Jeor and MET are two different formulas, shown separately.

Expected gain

kg/week

Approximation: ≈7,700 kcal per kg

Time to goal

weeks

Add a goal above your current weight

The kg-per-week figure borrows the standard weight-loss rule (about 7,700 kcal per kg). How fast you actually gain depends on how much of it is muscle and how active you are, so treat the timeline as rough.

Your results are attached to the form below

These figures are estimates for general awareness only and are not medical advice or a diagnosis. Read our Medical Disclaimer.

Want a Plan Built Around Your Numbers?

A certified dietitian will turn these figures into a diet that fits your routine and your food.

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How this is calculated

Maintenance = BMR × activity factor, with BMR shown two ways, separately: Mifflin-St Jeor (1990) and the MET method (24 kcal per kg per day for men, 22.5 for women), using the same activity ranges as our homepage calculator. Target = maintenance + your chosen surplus. Expected gain uses about 7,700 kcal per kg — the figure behind the standard weight-loss rule (US NIH, 2000) — as an approximation; no comparable official figure exists for adult weight gain. BMI uses the Indian cut-offs our clinic applies (healthy 18–22.9).

Check whether you need to gain

A BMI under 18 is underweight by the Indian cut-offs we use. If your BMI is already in the healthy range or above, gaining more weight may not help you — building muscle while staying at a similar weight is a different plan, and one a dietitian can design with you.

Gaining the right kind of weight

  • Add calories steadily rather than with large, greasy meals — an extra snack or a bigger breakfast is often enough.
  • Include protein at every meal: dal, paneer, curd, eggs, chicken or fish. Our Protein Calculator shows how much you need.
  • Combine extra food with strength training so more of the gain is muscle.

When to see a doctor

Unexplained weight loss, or being unable to gain despite eating more, can have a medical cause such as thyroid problems or diabetes. Get it checked before starting a weight-gain plan.

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