A calorie surplus means eating more than your TDEE so your body has spare energy to build muscle. A moderate surplus of 5–10% above maintenance is usually enough: 10% for beginners, 7.5% for intermediates and 5% for advanced lifters. For a woman with a TDEE of 2,239 kcal, a 10% surplus is about 2,463 kcal per day.
Key takeaways
- A 5–10% surplus above maintenance is a sensible bulking range; bigger surpluses mostly add fat.
- Beginners can use a larger surplus than advanced lifters, because they build muscle faster.
- The monthly gain shown is total body weight, only part of which will be muscle.
- Protein at about 1.6–2.2 g per kg and resistance training are what direct the surplus toward muscle.
How does this calorie surplus calculator work?
Enter your sex, age, weight, height, activity level and training experience (new, intermediate or advanced). The calculator estimates your TDEE with Mifflin–St Jeor (Mifflin et al., 1990), applies a surplus of 10%, 7.5% or 5% by experience, and shows your target calories, expected gain per month and a protein range of 1.6–2.2 g per kg. A table lists +5%, +10% and +15% targets.
What is a calorie surplus?
A calorie surplus is eating more energy than you burn. The extra energy can be stored as muscle, fat or both. Resistance training and enough protein push more of it toward muscle (Morton et al., 2018; Jäger et al., 2017).
target calories = TDEE × (1 + surplus %) monthly gain (kg) = daily surplus × 30 ÷ 7,700
The 7,700 kcal per kg figure is a planning approximation; real weight change varies and slows as your body adapts (Hall et al., 2011).
Worked example
A 35-year-old woman who is 5′5″ (165 cm), weighs 165 lb (74.8 kg) and is moderately active has a TDEE of 2,239 kcal.
| Surplus | Target | Extra per day | Expected gain per month |
|---|---|---|---|
| +5% | 2,351 kcal | 112 kcal | 1.0 lb (0.44 kg) |
| +7.5% | 2,407 kcal | 168 kcal | 1.4 lb (0.65 kg) |
| +10% | 2,463 kcal | 224 kcal | 1.9 lb (0.87 kg) |
| +15% | 2,574 kcal | 336 kcal | 2.9 lb (1.31 kg) |
Her protein range is 120–165 g per day. The same table for a 30-year-old man at 5′10″ and 190 lb (86.2 kg), moderately active, with TDEE of 2,834 kcal:
| Surplus | Target | Extra per day | Expected gain per month |
|---|---|---|---|
| +5% | 2,975 kcal | 142 kcal | 1.2 lb (0.55 kg) |
| +7.5% | 3,046 kcal | 213 kcal | 1.8 lb (0.83 kg) |
| +10% | 3,117 kcal | 283 kcal | 2.4 lb (1.10 kg) |
| +15% | 3,259 kcal | 425 kcal | 3.7 lb (1.66 kg) |
His protein range is 138–190 g per day.
How big a surplus do I need?
The calculator scales the surplus to experience. Beginners gain muscle fastest, so +10% is reasonable. Intermediates get +7.5% and advanced lifters +5%, because the rate of muscle gain slows with experience and the unused extra calories mostly become fat. These surplus sizes are TDEECalc defaults, chosen to limit fat gain.
Most of the monthly gain in the tables won’t be muscle. Water, glycogen and some fat come with it. A good result is a slow, steady weight trend and a waist that grows slowly.
Calorie surplus vs bulking calculator
They are the same thing. This page doubles as a bulking calculator: it sets the calories and protein, and the macro calculator turns the target into carb and fat grams. A gain-goal split there is 25% protein, 50% carbs and 25% fat.
How do I make sure the surplus builds muscle?
- Train with resistance exercise 2–4 times a week and aim for progressive overload.
- Hit your protein range every day. See the protein calculator.
- Weigh in several times a week and track the trend. If you gain faster than planned, trim 100–200 kcal.
- Confirm your starting point with the maintenance calories page.
Talk to a doctor or registered dietitian before bulking if you have a history of disordered eating, diabetes or other conditions affected by diet.
Frequently asked questions
How big should a calorie surplus be?
For most people 5–10% above maintenance. Beginners can use the upper end, intermediate lifters about 7.5%, and advanced lifters about 5%. Larger surpluses tend to add more fat than muscle.
How do I calculate a calorie surplus?
Find your maintenance calories (TDEE), then multiply by 1.05–1.10 for a 5–10% surplus. For maintenance of 2,239 kcal, 1.10 gives 2,463 kcal. The calculator does this and also shows expected monthly weight gain.
How much weight will I gain on a surplus?
Weight gain is roughly surplus × 30 ÷ 7,700 kg per month. A 224 kcal daily surplus is about 0.87 kg (1.9 lb) per month. Real gains vary with water, glycogen and how your body adapts, so judge by a multi-week trend.
What is the difference between a lean bulk and a dirty bulk?
A lean bulk uses a small surplus (about 5–10%) to limit fat gain. A dirty bulk eats freely with a large surplus, which tends to add more fat for the same muscle. The moderate approach suits most people and is easier to cut back from.
Do I need a surplus to build muscle?
Not always. Beginners and people returning to training can build muscle at maintenance, as covered in the body recomposition calculator. A surplus becomes more important as you get more experienced and gains slow down.
When should I stop bulking?
When you reach a goal weight or body fat you are comfortable with, or when your waist grows faster than your strength. Then return to maintenance calories, or start a deficit using the calorie deficit calculator.
References
- Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO (1990). A new predictive equation for resting energy expenditure in healthy individuals. American Journal of Clinical Nutrition 51(2):241–247.
- Morton RW, Murphy KT, McKellar SR, et al. (2018). A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. British Journal of Sports Medicine 52(6):376–384.
- Jäger R, Kerksick CM, Campbell BI, et al. (2017). International Society of Sports Nutrition Position Stand: protein and exercise. Journal of the International Society of Sports Nutrition 14:20.
- Hall KD, Sacks G, Chandramohan D, et al. (2011). Quantification of the effect of energy imbalance on bodyweight. The Lancet 378(9793):826–837.