Calorie Surplus Calculator: Plan a Gradual Weight Gain

How the calorie surplus estimate is calculated

The page adds two numbers: daily intake = maintenance + surplus. Maintenance is the intake that would hold your weight steady. The surplus is how much more you plan to eat each day.

It then turns the surplus into a weekly figure with the familiar 3,500 kcal per pound, or 7,700 kcal per kilogram: surplus × 7 ÷ 3,500 gives pounds per week. The calorie deficit calculator uses the same step in the other direction, and the maintenance calories calculator uses the 7,700 kcal per kg figure to work backward from a weight log.

The planning band

The presets are +250 and +500 kcal/day. Aragon and Schoenfeld (2020) describe a surplus of roughly 250 to 500 kcal/day above maintenance for trained lifters, about 10 to 20%. Iraki and colleagues (2019) describe about 10 to 20% above maintenance for novice and intermediate lifters in the off-season, and a weekly gain of about 0.25 to 0.5% of body weight. At 2,749 kcal/day, 10% is about 275 kcal and 20% is about 550 kcal, close to the two presets.

There is no single correct surplus. The published bands change with training experience, and Aragon and Schoenfeld (2020) describe 500 to 1,000 kcal/day for beginners. This page starts at the smaller band because it is the more conservative of the two. You can type any surplus you like.

Calorie surplus examples

The starting maintenance is 2,749 kcal/day, the default result on the maintenance calories calculator. If you only have a formula estimate from the TDEE calculator, enter that instead. Adding 250 gives 2,749 + 250 = 2,999 kcal/day. Under the static rule, 250 × 7 ÷ 3,500 is about 0.5 lb a week, or 250 × 7 ÷ 7,700, about 0.23 kg a week.

Adding 500 gives 2,749 + 500 = 3,249 kcal/day, which the same rule calls about 1.0 lb or 0.45 kg a week.

Someone whose logged maintenance is 2,200 kcal/day and who picks +250 would aim for 2,450. The arithmetic is the same at any maintenance number.

Why the weekly figure is only a planning number

A fixed surplus does not keep producing the same weekly change. As weight rises, the energy needed to hold it rises too, and day-to-day movement can change without you noticing. Kevin Hall and Carson Chow (2013) explain why static 3,500 kcal rules over-predict long-term change. Water, stored carbohydrate and salt also move the scale from day to day.

Treat the weekly number as a starting guess. Weigh in under the same conditions several times a week, look at the trend over three or four weeks, and adjust the surplus a little if the trend is far from the plan. The maintenance calories calculator can turn that log into a new maintenance number.

The page also does not say how much of any gain is muscle. Garthe and colleagues (2013) found that elite athletes on a larger planned surplus gained slightly more lean mass but clearly more fat than those eating freely. This page does not model what decides that split.

Large surpluses

If the surplus is above 1,000 kcal/day or above 25% of the maintenance number entered, the page adds a note. That is the same cut-off the calorie deficit calculator uses for a large gap, and it is a reminder that the static rule gets less reliable as the gap grows, not a limit.

Limits of the estimate

The result is only as good as the maintenance number you enter. A formula estimate can be off by a few hundred calories for a given person, and a logged estimate depends on how complete the log is. The page plans energy only. It does not set protein, carbohydrate or fat amounts. This is an estimate for general fitness planning, not medical advice.

Sources

Aragon AA, Schoenfeld BJ. Magnitude and composition of the energy surplus for maximizing muscle hypertrophy: implications for bodybuilding and physique athletes. Strength Cond J. 2020;42(5):79–86. doi:10.1519/SSC.0000000000000539.

Iraki J, Fitschen P, Espinar S, Helms E. Nutrition recommendations for bodybuilders in the off-season: a narrative review. Sports (Basel). 2019;7(7):154. doi:10.3390/sports7070154. PMID 31247944.

Hall KD. What is the required energy deficit per unit weight loss? Int J Obes. 2008;32(3):573–576. doi:10.1038/sj.ijo.0803720. PMID 17848938.

Hall KD, Chow CC. Why is the 3500 kcal per pound weight loss rule wrong? Int J Obes. 2013;37(12):1614. doi:10.1038/ijo.2013.112. PMID 23774459.

Garthe I, Raastad T, Refsnes PE, Sundgot-Borgen J. Effect of nutritional intervention on body composition and performance in elite athletes. Eur J Sport Sci. 2013;13(3):295–303. doi:10.1080/17461391.2011.643923.

Sources last checked: 15 October 2026.

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