Bulking Calculator
Plan a lean bulk with maintenance calories, surplus size, and macro targets tuned for muscle gain. The calculator favors controlled bulks that support performance without unnecessary fat gain.
Mifflin-St Jeor maintenance estimate · goal-based calorie surplus of 200 to 450 kcal/day
Clear numbers first, practical next steps after.
Every calculator is built to give you an estimate you can actually use for nutrition, training, or body-composition planning.
What separates a lean bulk from a dirty bulk
A lean bulk is controlled enough that training performance improves while fat gain stays manageable. The point is not to gain weight as fast as possible, but to spend more of that gain on useful tissue.
The faster you force body weight up, the more likely the extra calories mostly turn into body fat instead of better training output.
How to judge whether your bulk is working
Look for improvements in load, reps, work capacity, and recovery alongside a slow body-weight rise. If body weight climbs fast without better gym performance, the surplus is probably too large.
A lean bulk is successful when it sets up a smaller, easier cut later.
Frequently Asked Questions
How big should a bulking surplus be?
For most natural lifters, smaller surpluses work better. Around 200 to 350 calories above maintenance is often enough to support productive training without excessive fat gain.
What rate of gain is ideal in a bulk?
That depends on training age. Many intermediates do well gaining around 0.25 to 0.5 percent of body weight per week. Faster rates usually increase fat gain.
Should protein stay high while bulking?
Yes, but you usually do not need cutting-level protein. Around 1.6 to 2.2 grams per kilogram of body weight is a strong range for muscle gain phases.
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Run your bulk with objective feedback
Keep calories, body weight, and gym progression connected so you can tell whether your surplus is actually buying better performance.