Weight Cut Calculator for Combat Sports

In combat sports, weight cuts can be expressed as a percentage of body mass, and the time available for recovery is also an important consideration.5,6 This tool shows your planned cut as a percentage and places it against what research on combat athletes has reported. It describes the research; it is not a weight-cutting plan.

Current weight (kg)
Weigh-in limit (kg)
Days to weigh-in

Why percentages matter

A systematic review of combat-sport athletes reported weight loss both in kilograms and as a percentage of body mass.2 Pre-competition weight loss is extremely common: a 2024 systematic review of 26 studies and nearly 4,000 athletes found it to be highly prevalent across combat sports (its results section reports 66–100%, although one included study reported 59%).2

Size and speed

The magnitude and speed of weight loss are both critical.1 Rapid cuts lean on fluid loss, which is why the time available to rehydrate after the weigh-in matters.5,7

References

Every figure and statement in this tool is linked to a source: the original study where my article cites one, otherwise my own article on the topic. The small numbers in the text refer to this list.

  1. Lee 2026. Effects of Rapid Weight Loss on the Immune System in Combat Sports Athletes: A Systematic Review. Int J Mol Sci.
  2. Weight loss in combat sports (systematic review)
  3. Mauricio et al. 2022. Rapid Weight Loss of Up to Five Percent of the Body Mass in Less Than 7 Days Does Not Affect Physical Performance in Official Olympic Combat Athletes With Weight Classes: A Systematic Review With Meta-Analysis. Front Physiol.
  4. Study cited in “Weight Cutting in Combat Sports: What the Evidence Actually Shows About Performance and Health Risk” (reference 4)
  5. Jetton et al. 2013. Dehydration and Acute Weight Gain in Mixed Martial Arts Fighters Before Competition. Journal of Strength and Conditioning Research.
  6. Dr. Antti Rintanen: Weight Cutting in Combat Sports: What the Evidence Actually Shows About Performance and Health Risk
  7. Study cited in “Weight Cutting in Combat Sports: What the Evidence Actually Shows About Performance and Health Risk” (reference 2)

Sources

This tool is based on the articles below and the studies cited in them:

This tool is for general education. It does not interpret your own results, give personal recommendations or replace an assessment by your doctor.