Can you make
the weight?

What weight should I fight at?

The right class is one you can reach mostly by losing fat during camp, with only a small cut at the end. Three numbers from the research help you check it:

• Between camps: stay about 12–15% above your division limit (ISSN, 2025).
• During camp: lose about 0.5–1 kg (1.1–2.2 lb) a week (ISSN, 2025).
• Water: losing 2–3% of body mass as fluid likely has few downsides if you recover aggressively, but relying on more than 3% may hurt health and performance (ACSM, 2021).

If the calculator says the cut is too fast, you have two honest options: more weeks, or the next class up. Being the bigger fighter matters less than most think; in MMA, studies have not found a link between weight regained after the weigh-in and winning (ACSM, 2021).

How the calculator works

It splits your cut into two parts. The final days take up to 4.4% of your body weight with a day-before weigh-in, the ISSN's 24-hour figure and the most cautious of its fight-week limits. With a same-day weigh-in it uses 2%, from lower glycogen and fibre only, since there's no time to refill water (ISSN, 2025; Reale et al., 2017).

Everything above that has to come off in camp. The calculator divides it by your weeks to weigh-in and compares the pace with 0.5–1 kg a week. Above 1 kg a week, the cut is marked as too fast.

The step-by-step version, with a worked example, is in how much weight can you cut for a fight.

Frequently asked questions

What weight should I fight at?

Pick the class you can reach mostly through fat loss in camp. The ISSN suggests staying about 12–15% above your division limit between camps and losing about 0.5–1 kg a week during camp. If the calculator shows you need more than 1 kg a week, or you sit more than 15% above the limit today, the next class up is usually the better choice.

How much weight can I cut in the last few days?

With a weigh-in the day before, the ISSN lists upper limits of about 6.7% of body mass at 72 hours, 5.7% at 48 hours and 4.4% at 24 hours. The calculator uses 4.4%, the most cautious of the three. These are ceilings for experienced, supervised fighters, not targets.

Why does a same-day weigh-in change the result?

With only a few hours between weigh-in and competing, you can't refill a water cut. The calculator then only counts lower glycogen and lower fibre, which the ISSN puts at about 1–2% of body mass each, and uses 2% in total. The rest has to come off in camp.

Is the calculator safe to follow?

It is general information, not medical advice. It shows whether a goal fits within published guidelines, not that it is safe for you. If you are under 18, new to the sport, have a medical condition or are unsure, choose your class with your coach and a doctor.

Important

This calculator is general information, not medical advice. The limits it uses are upper bounds for experienced adults with supervision and time to recover, not targets. Heavy cuts and dehydration can be dangerous. If you feel dizzy, confused or unwell during a cut, stop and seek help.

By Simon Jounan