Find exactly how many calories to eat to build muscle with minimal fat gain, evidence-based lean bulk targets built around your TDEE.
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Muscle vs fat projection
Metric & imperial
Calorie Surplus Calculator
Based on your TDEE & chosen bulk pace
yrs
kg
cm
Sedentary
Desk job, no exercise
Light
1-3x / week
Moderate
3-5x / week
Very Active
6-7x / week
Athlete
Twice daily
Lean Bulk
+200 kcal
Minimal fat gain Slower muscle growth
Moderate
+350 kcal
Balanced approach Recommended
Aggressive
+500 kcal
Faster gains More fat accumulation
Your TDEE (Maintenance)
-
kcal / day
Your Surplus Target
-
kcal / day
-
Weight / Week
-
-
Est. Muscle / Month
Based on experience level
-
Est. Fat / Month
Approximate accumulation
12-Week Gain Projection
Muscle
Fat
Suggested Macros at Surplus
Protein
-
Carbs
-
Fat
-
Train Hard
Surplus calories only turn into muscle if you're giving your body a reason to build it. Progressive overload is non-negotiable.
Track Weekly
Weigh yourself daily and use the weekly average. Gaining more than ~0.5kg/week likely means too much fat accumulation.
Recalculate Often
As you gain weight your TDEE increases. Recalculate every 4-6 weeks to keep your surplus accurate.
Muscle gain projections are estimates based on research averages. Individual results vary significantly based on training quality, sleep, genetics and consistency.
The Guide
How To Calculate Your Calorie Surplus For Muscle Gain
A calorie surplus means eating more calories than your body burns in a day. The extra energy provides the raw material your body needs to synthesise new muscle tissue, but only if you're training with sufficient intensity and volume. Get the surplus right and you build mostly muscle. Get it wrong and you mostly gain fat.
The foundation is your TDEE, the total calories you burn daily. Add your chosen surplus on top of that and you have your daily calorie target for bulking.
How Big Should Your Surplus Be?
Approach
Daily Surplus
Best For
Fat Risk
Lean Bulk
+200 kcal
Experienced lifters, low body fat
Minimal
Moderate Bulk
+350 kcal
Most people, best balance
Low
Aggressive Bulk
+500 kcal
Beginners, hard gainers
Moderate
Why You Can't Just Eat Everything
There's a ceiling on how fast muscle can be built, your body can only synthesise so much new tissue per week regardless of how many calories you eat. Beginners can gain roughly 0.9-1.1 kg of muscle per month, intermediates around 0.45-0.7 kg, and advanced lifters closer to 0.2-0.45 kg. Calories above what's needed for that maximum rate simply become fat.
This is why a massive "dirty bulk" is inefficient, you spend months gaining fat you then have to cut off, which costs you time and risks losing some of the muscle you worked hard for.
The Role of Protein in a Surplus
Even in a calorie surplus, protein is the most important macro. Aim for 1.6-2.2g per kg of bodyweight to maximise muscle protein synthesis. The surplus calories above your protein target should be split between carbohydrates (which fuel your training and support recovery) and fats (essential for hormonal health). At a surplus, carbohydrates should be prioritised higher than at maintenance because your training volume and intensity should also be increasing.
When To Switch From Bulk To Cut
Most lifters bulk until they reach around 15-18% body fat (men) or 25-28% body fat (women), then cut back to a leaner baseline. Bulking beyond these ranges makes the subsequent cut longer and harder, and higher body fat is associated with a less favourable hormonal environment for muscle growth anyway. Track your body composition throughout, not just your weight.
Frequently Asked Questions
Most effective bulk phases run 3-6 months. Shorter than 3 months doesn't give you enough time to accumulate meaningful muscle gain. Longer than 6 months without a reassessment risks excessive fat gain and metabolic adaptation. After a bulk, most lifters do a maintenance phase or cut before starting again.
Generally, cut first if you're above 18% body fat (men) or 28% (women). A leaner starting point means better insulin sensitivity, a more favourable hormonal environment for muscle growth, and less fat to lose at the end. If you're close to those thresholds, a body recomposition approach (small surplus or maintenance) may be more appropriate.
If you're not gaining after 2 weeks, increase your intake by 150-200 kcal and reassess. Common causes of stalled bulk weight gain: underestimating calories burned (your TDEE is higher than calculated), not tracking food accurately, or subconsciously moving less (NEAT reduction). Add calories incrementally rather than making large jumps.
Yes, body recomposition is possible, particularly for beginners, people returning after a break, or those with higher body fat. It requires eating at or very slightly above maintenance, high protein, and consistent progressive training. Results are slower than a dedicated bulk, but you simultaneously lose fat and gain muscle.
Total daily calories and protein matter far more than timing. That said, distributing protein evenly across 3-5 meals (rather than one huge meal) maximises muscle protein synthesis throughout the day. Eating enough carbohydrates before and after training sessions also supports performance and recovery.
