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Combat Sports Weight Cut Calculator

Calculate the rate of weight loss needed to safely reach a target weigh-in weight.

Result

Total to Lose
20 lb
% of Bodyweight
11.4%
Weekly Rate Needed
10 lb/week

This exceeds 10% of bodyweight, which is generally considered an aggressive cut carrying meaningful health and performance risk - consult a sports medicine professional or licensed dietitian before attempting large weight cuts.

About the Weight Cut Calculator

This calculator estimates the pace of weight loss a combat sports athlete would need to hold in order to reach a target weigh-in weight by a given date. It is aimed at wrestlers, boxers, and MMA fighters planning a weight cut ahead of an official weigh-in.

How It Works

Enter current weight, target weigh-in weight, and the number of days remaining until weigh-in. The calculator finds the total pounds to lose, expresses that as a percentage of current bodyweight, and converts it into a required weekly rate of loss over the remaining days.

Total to Lose = Current Weight - Target Weight; % of Bodyweight = (Total to Lose / Current Weight) x 100; Weekly Rate = (Total to Lose / Days Until Weigh-In) x 7

Formula & Methodology

Subtract the target weigh-in weight from the current weight to find the total pounds that need to come off. Divide that figure by current weight and multiply by 100 to express it as a share of total bodyweight, which is the standard way weight-cut aggressiveness is discussed in combat sports. Then divide the total to lose by the number of days remaining and multiply by 7 to convert that daily pace into an equivalent weekly rate, useful for comparing against general guidelines for sustainable loss.

Examples

Standard 14-day cut

An athlete weighing 175 lb wants to hit 155 lb in 14 days. Total to lose is 20 lb, which is 11.4% of bodyweight, and the weekly rate needed is 10.0 lb/week, a pace the calculator flags as an aggressive cut given it exceeds 10% of bodyweight.

Gradual month-long cut

The same 175 lb athlete instead plans a 155 lb weigh-in over 28 days. Total to lose stays at 20 lb (11.4% of bodyweight), but the weekly rate needed drops to 5.0 lb/week, since the same total loss is spread across twice the time.

Advantages

  • Converts a target weigh-in date into a concrete weekly pace, useful for early-season cut planning rather than last-minute crash dieting.
  • Automatically flags cuts exceeding 10% of bodyweight, a commonly cited threshold for elevated risk.
  • Works for any combat sport with a scheduled weigh-in, not just one specific discipline.

Common Mistakes

  • Treating the weekly rate figure as a recommendation rather than what it actually is: the pace required to hit the target on schedule, which may or may not be safe or achievable.
  • Ignoring the aggressive-cut warning when it appears and planning around water-cutting alone instead of adjusting the timeline or target weight.
  • Not updating the calculator with current weight regularly, since the required weekly rate changes as both current weight and days remaining shift.
  • Assuming the percentage of bodyweight figure accounts for body composition, when it is a simple ratio of total pounds to current weight only.

Edge Cases to Watch For

  • If days until weigh-in is zero or entered as a negative number, the calculator blocks the calculation with an error rather than dividing by zero.
  • If the calculated cut exceeds 10% of current bodyweight, the tool displays a note flagging it as an aggressive cut with meaningful health and performance risk and recommending professional guidance.
  • A target weight higher than current weight produces a negative 'total to lose' and a negative weekly rate, which the calculator does not block, since it simply reflects a weight gain rather than a cut.
  • The math only accounts for total weight change over time; it does not model water manipulation, rehydration, or how much of the loss is fat, muscle, or fluid.

Common Use Cases

  • Wrestlers and MMA fighters mapping out a cut timeline in the weeks before an official weigh-in.
  • Coaches and cutting teams checking whether a proposed weight-class jump is realistic given the time available.
  • Athletes comparing a rushed short-notice cut against a longer, more gradual plan for the same target weight.
Written & fact-checked by the Calculateus TeamLast updated August 5, 2026How we verify our formulas

Frequently asked questions

Why do combat sport athletes cut weight before weighing in?

Weigh-ins typically happen 24-36 hours before competition, so athletes can shed weight (often significant amounts of water) to make a lower weight class, then rehydrate and refuel before competing at a higher effective bodyweight than their opponents - this is a legal but potentially risky and controversial practice, this calculator provides general math only, not medical guidance.

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Conclusion

This tool provides the arithmetic behind a weight cut, not a diet or hydration plan, and it deliberately flags cuts above 10% of bodyweight as carrying elevated risk. Athletes weighing a fast cut against a slower one can use it to see exactly how the required weekly pace changes with the timeline.