How Long Should a Cut Last?
By CoachAk · · 6 min read
How long should a cut last? Long enough to lose the fat you want at a pace that keeps your muscle, and no longer. Your number comes from simple maths: how much you want to lose, divided by how fast you can sensibly lose it. Here is how to work it out, what typical cuts look like, and when to stop early.
The short answer
- Weeks needed = weight to lose ÷ weekly rate of loss.
- A sensible rate is about 0.5 to 1% of your body weight a week (Helms and colleagues, 2014).
- Losing 5 kg (11 lb) at 0.5 kg (1.1 lb) a week takes about 10 weeks; losing 10 kg (22 lb) takes about 20, before allowing for the slowdown as you get lighter.
- For scale: the NHS Weight Loss Plan runs for 12 weeks, and in a 2018 study of 51 natural bodybuilders, contest prep diets lasted about 22 weeks on average.
- Pause or stop early if training, sleep, mood or your menstrual cycle are suffering, or if life gets in the way.
- On a long cut, diet breaks at maintenance can make it easier to stick to, but they add weeks.
How long should a cut last? Work it out in three steps
1. Decide how much you want to lose
A target weight is the easiest place to start. If you want to aim for a body-fat level instead, estimate your body fat with the free body fat calculator. Then:
- Fat mass = body weight × body-fat percentage.
- Everything else (lean mass) = body weight − fat mass.
- Target weight = lean mass ÷ (1 − target body-fat percentage).
Example: you weigh 85 kg (187 lb) at about 22% body fat. Your fat mass is about 18.7 kg and the rest is about 66.3 kg. To reach 15% while keeping your lean mass, your target weight is 66.3 ÷ 0.85 ≈ 78 kg (172 lb). That is about 7 kg (15 lb) to lose.
Body-fat estimates are rough, whatever the method, so treat the result as a guide and let the mirror, your waist measurement and your photos have the final say.
2. Choose a weekly rate
In their 2014 recommendations for natural bodybuilders, Helms and colleagues advise losing about 0.5 to 1% of your body weight a week to keep as much muscle as possible, and warn that the leaner you get, the greater the risk of losing muscle. The NHS suggests 0.5 to 1 kg (1 to 2 lb) a week for weight loss in general.
- Leaner, or close to your goal: stay near 0.5%.
- More fat to lose: you can usually start nearer 1%.
3. Divide
| Weight to lose | At 0.4 kg (0.9 lb) a week | At 0.6 kg (1.3 lb) a week | At 0.8 kg (1.8 lb) a week |
|---|---|---|---|
| 4 kg (9 lb) | 10 weeks | about 7 weeks | 5 weeks |
| 7 kg (15 lb) | about 18 weeks | about 12 weeks | about 9 weeks |
| 10 kg (22 lb) | 25 weeks | about 17 weeks | about 13 weeks |
| 15 kg (33 lb) | about 38 weeks | 25 weeks | about 19 weeks |
Then add some slack. Loss slows as you get lighter, because a smaller body burns less and your body adapts to the diet; Helms and colleagues point out that calories need adjusting as body mass falls. Holidays, illness and busy weeks happen too.
If the answer is much longer than you hoped, that is useful to know before you start, not halfway through. Split a big goal into two or three shorter cuts with time at maintenance between them. How to start a cut covers setting up the first few weeks.
How long do cuts usually last?
There is no single right length, but these give a sense of scale:
| Example | Length |
|---|---|
| The NHS Weight Loss Plan | 12 weeks |
| Continuous dieting group in the ICECAP trial (Peos and colleagues, 2021) | 12 weeks |
| Traditional contest prep, according to Helms and colleagues | 2 to 4 months |
| Average contest prep in 51 natural bodybuilders (Chappell and colleagues, 2018) | About 22 weeks |
Helms and colleagues suggest that longer, slower preps may keep more muscle than short, aggressive ones. By their sums, someone at about 70 kg (154 lb) and 13% body fat would need to start no more than 6 to 7 kg (13 to 15 lb) above stage weight to get stage-lean in a traditional three-month prep at 0.5 kg (1.1 lb) a week.
Why a cut should not go on forever
The longer and leaner you diet, the harder your body pushes back.
- Hormones drop. In a 2013 case study by Rossow and colleagues, a natural bodybuilder went from 14.8% to 4.5% body fat over six months of prep. By the end of prep, his testosterone had fallen to about a quarter of its starting level, before recovering after the show.
- Periods can change. In a 2017 study by Hulmi and colleagues, 27 women dieted for four months for a fitness competition. Leptin, thyroid hormone, testosterone and oestrogen fell, and menstrual irregularities became more common. Most hormones were back to normal three to four months later; thyroid hormone and testosterone were not.
- Energy can run too low. The International Olympic Committee's 2023 consensus statement on relative energy deficiency in sport (REDs) describes what happens when energy intake does not cover the cost of training for long enough: problems with menstrual health, bone health and digestion, as well as disordered eating.
The bodybuilder and the fitness competitors were chasing stage condition, far leaner than most people need. But they show why a cut is a phase, not a lifestyle.
Signs it is time to pause or stop
End the cut, or take a break at maintenance, if:
- you have reached your goal, or close enough that the last bit is not worth it;
- your strength is dropping week after week, not just on one bad day;
- sleep, mood or sex drive have clearly worsened;
- hunger is constant and you think about food most of the day;
- your periods have become irregular or stopped (speak to your doctor about this);
- life is about to get harder: a new job, exams, a new baby or a stressful month.
Stopping early is not failing. Holding your new weight at maintenance for a while is a result in itself.
Diet breaks: a pause that makes long cuts easier
A diet break is a week or two eating at maintenance in the middle of a cut. In the ICECAP trial, lifters who dieted in 3-week blocks with a 1-week break between them got about the same results as those who dieted straight through, over 15 weeks rather than 12, and reported less hunger. In the MATADOR study (Byrne and colleagues, 2018), sedentary men with obesity who alternated 2 weeks of dieting with 2 weeks at maintenance lost more fat than those who dieted continuously, but the plan took 30 weeks instead of 16.
So breaks do not speed things up. They make a long cut easier to stick to, at the cost of a later finish date. Diet breaks and refeeds covers the research and how to run one.
What happens when the cut ends
Do not jump straight from your diet back to your old eating. Bring calories up to your new maintenance, which is lower than before because you weigh less, and give your body a few weeks to settle. A little weight comes back as glycogen and water when you eat more carbohydrate, and that is not fat. Reverse dieting compares going straight to maintenance with getting there in steps.
How coaching helps
The hard part of a cut is not the maths. It is knowing whether a stall means "keep going", "adjust" or "stop". With one-to-one coaching from CoachAk, your calorie, macro and step targets live in a private app, and you log your weight daily against a smoothed trend. Each weekly check-in covers your weight, training and nutrition adherence, steps, sleep, energy, hunger, stress and body measurements, with optional progress photos side by side. Your coach replies with written feedback and adjusts your plan, including when to take a break and when to finish.
If you want a cut with a clear plan and a clear end, apply for coaching.
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