Weight Gain Calculator

Calories and weeks needed to reach a higher goal weight. Free, private and instant.

How to use the Weight Gain

  1. Pick metric (cm, kg) or imperial (ft, in, lb) units.
  2. Choose sex: Male or Female.
  3. Enter age.
  4. Enter height.
  5. Enter weight.
  6. Choose activity level: Sedentary (little or no exercise), Lightly active (1-3 days/week), Moderately active (3-5 days/week), Very active (6-7 days/week) and more.
  7. Enter goal weight.
  8. Choose weekly weight-gain pace: 0.25 kg per week (lean gain), 0.5 kg per week (faster) or 0.75 kg per week (aggressive).
  9. Press Calculate to get an instant result with a colour scale, chart and plain-English explanation.

About the Weight Gain

The weight gain calculator shows how many calories to eat above maintenance to gain weight at a steady pace, how long it should take and how much protein to aim for. It is useful for underweight adults and for people building muscle.

Also known as: calories to gain weight, bulking calculator, weight gain plan calculator, how to gain weight calculator.

Formula and cut-offs

Daily target = TDEE + (weekly gain x 7,700 kcal / 7). Protein target = 1.8 g per kg body weight. Projection recalculates maintenance each week as weight rises.

Frequently asked questions

How many calories should I eat to gain weight?

A surplus of 250 to 500 kcal above maintenance suits most people and favours lean gain over fat.

How fast can I gain muscle?

Beginners may gain 0.25 to 0.5 kg of muscle a month with training. Faster weight gain is mostly fat.

Should underweight people see a doctor?

Yes. Unplanned low weight can have medical causes, so check with a doctor or dietitian.

Sources and references

Written and checked by the MediHub editorial team against the sources above. Read how we build and review our calculators.

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Last updated . This calculator is for education only and is not medical advice. See the medical disclaimer.