Bulking and Cutting: How to Gain Muscle and Lose Fat the Right Way
Lean bulk on a surplus of about 10–20% above maintenance and aim to gain roughly 0.25–0.5% of bodyweight per week. Cut at about 0.5–1% of bodyweight per week with high protein. If you are unsure which to do first, the decision table below helps.
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General education, not medical advice. AI-assisted research and drafting, human-edited and checked against the cited sources. How we work.
Key takeaways
- Lean bulk on a small surplus (~200–350 kcal).
- Cut on a moderate deficit (~300–500 kcal).
- Target 0.25–0.5% body-weight change per week.
- Keep protein at 1.6–2.2 g/kg in both phases.
- Never gut your training volume during a cut.
On this page
Bulk, cut, and why phases exist
Building muscle needs a small calorie surplus; losing fat needs a deficit. Because building muscle and losing fat at the same time is difficult for most trained lifters, many people alternate phases. The goal isn't extreme — it's a controlled bulk followed by a patient cut, keeping most of the muscle you built.
| Your situation | Usual starting point | Why |
|---|---|---|
| New to lifting, average body fat | Maintenance or small surplus | Beginners can gain muscle with little surplus |
| Higher body fat, want to look leaner | Cut | Losing fat first makes the later bulk easier to judge |
| Lean, gaining slowly, eating little | Lean bulk | A small surplus supports growth |
| Returning after a long break | Maintenance (recomp) | Muscle regain is often quick at maintenance |
This is a coaching framework; individual goals and health matter more than the table.
How big should a bulk be?
Keep it lean: a surplus of roughly 10–20% above maintenance, aiming for about 0.25–0.5% of body weight gained per week. Faster than that is mostly fat, which just means a longer, harder cut later. Prioritize protein at 1.6–2.2 g/kg per the ISSN Position Stand — Protein and Exercise (JISSN) and let training drive where those calories go.
| Bodyweight | Lean bulk: 0.25–0.5%/wk | Cut: 0.5–1%/wk |
|---|---|---|
| 60 kg | 0.15–0.30 kg | 0.30–0.60 kg |
| 70 kg | 0.18–0.35 kg | 0.35–0.70 kg |
| 80 kg | 0.20–0.40 kg | 0.40–0.80 kg |
| 90 kg | 0.23–0.45 kg | 0.45–0.90 kg |
| 100 kg | 0.25–0.50 kg | 0.50–1.00 kg |
Bulking rates follow Iraki et al. (2019), with a surplus of roughly 10–20% above maintenance. Cutting rates follow Helms et al. (2014).
How to cut without losing muscle
Run a moderate deficit of about 300–500 calories for about 0.5–1% of body weight lost per week. Two rules protect muscle: keep protein high (often toward the upper end, 2.3–3.1 g/kg of lean body mass during a cut) and keep lifting heavy — the Morton et al. — Protein supplementation & resistance training meta-analysis (PubMed) and resistance training preserve lean mass in a deficit. Crash diets torch muscle and metabolism.
Worked example: setting a lean-bulk target
Maintenance from the TDEE calculator is 2,700 kcal. A 10% surplus is 270 kcal, so the starting target is about 2,970 kcal. For a 75 kg lifter, the goal is 0.19–0.38 kg of gain per week. Weigh daily, compare weekly averages, and adjust by about 100–150 kcal if the average moves faster or slower than this for two weeks.
How long should phases last?
Bulks of 3–5 months and cuts of 8–16 weeks are typical. Don't cut forever — take diet breaks at maintenance to support training quality and adherence. The yo-yo trap comes from extremes; slow, boring consistency wins the long game.
Protein and training in both phases
Whether you are gaining or losing, keep protein around 1.6–2.2 g/kg and keep lifting hard. In a surplus that protein and training turn extra calories into muscle; in a deficit they signal your body to hold onto the muscle it has. Cutting is not the time to slash training volume — that is how people lose the size they built.
Cardio is the other lever in both phases, and it worries people more than it should. Cardio for muscle builders covers how much is safe while gaining and why volume usually rises during a cut.
The protein calculator will do that conversion for you. Note that it uses a slightly higher band while cutting (1.8–2.4 g/kg) than the 1.6–2.2 g/kg above, because some evidence suggests protein needs rise in a deficit; either range is defensible, and the difference matters less than hitting one of them consistently.
Common questions
Can I build muscle and lose fat at the same time?
True beginners, those returning after a break, and people with higher body fat can recomp for a while. Most trained lifters make faster progress by alternating focused bulk and cut phases.
How much protein during a cut?
Aim for the upper end, around 2.0–2.4 g/kg of body weight, to protect muscle while eating fewer calories. Combined with heavy lifting, this preserves lean mass.
How fast should I lose weight when cutting?
About 0.5–0.75% of body weight per week. Faster loss increasingly comes from muscle and is harder to sustain, so patience protects your hard-earned gains.
Limitations of this guide
Calorie calculators estimate, they do not measure. Use your scale trend to correct the starting number. These targets are for healthy adults; a history of disordered eating is a reason to work with a professional rather than follow weight-change targets.
References
- Iraki J, Fitschen P, Espinar S, Helms E (2019). Nutrition recommendations for bodybuilders in the off-season: A narrative review. Sports, 7(7), 154. PubMed (opens in a new tab)
- Helms ER, Aragon AA, Fitschen PJ (2014). Evidence-based recommendations for natural bodybuilding contest preparation: Nutrition and supplementation. Journal of the International Society of Sports Nutrition, 11, 20. PubMed (opens in a new tab)
- 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. British Journal of Sports Medicine, 52(6), 376–384. PubMed (opens in a new tab)
Related tool: TDEE & Macro Calculator. Maintenance calories from Mifflin-St Jeor (or Cunningham with body-fat %), five goal targets and a macro split.
Open the TDEE calculatorRelated guides
This guide is general fitness education and does not replace advice from a doctor, registered dietitian or qualified coach. Stop any exercise that causes sharp pain. See the full disclaimer.