Calorie Calculator for Weight Gain
To gain weight or build muscle you need a calorie surplus — eating more than you burn. Find your maintenance calories (TDEE) below, then add about 300–500 a day for a lean, steady gain. This page explains how to bulk without putting on excess fat and how much protein to pair with the extra calories.
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Frequently asked questions
How many calories should I eat to gain weight?+
Add about 300–500 calories a day above your TDEE for a lean gain of roughly 0.25–0.5 kg per week. Larger surpluses add weight faster but most of the extra is fat. Pair the surplus with resistance training and 1.6–2.2 g of protein per kg to bias the gain toward muscle.
How do I gain weight without gaining too much fat?+
Keep the surplus modest (around 300 calories), train with weights, prioritise protein, and gain slowly. Track your weight weekly and trim the surplus if you're gaining faster than about 0.5 kg a week.
How are my daily calories calculated?+
The calculator estimates your Basal Metabolic Rate (BMR) — the energy your body uses at rest — using the Mifflin-St Jeor equation from your age, sex, height and weight, then multiplies it by an activity factor to give your Total Daily Energy Expenditure (TDEE): the calories you burn in a typical day.
What is the difference between BMR and TDEE?+
BMR is what you'd burn lying in bed all day. TDEE is BMR plus the energy you spend moving, exercising and digesting food. To maintain your weight, eat around your TDEE; to lose or gain, adjust from there.
How many calories should I eat to lose or gain weight?+
A deficit of about 500 calories a day below your TDEE leads to roughly 0.5 kg of fat loss per week; a 500-calorie surplus supports a similar rate of gain. Avoid very large deficits, which are hard to sustain and can cost you muscle.
Are these calorie numbers exact?+
No — they're a well-validated estimate. Real needs vary with muscle mass, genetics and daily activity. Use the number as a starting point, track your weight for 2–3 weeks, and adjust by 100–200 calories if you're not moving in your intended direction.