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How to run a weigh-in: a practical guide for organisers and officials

A good weigh-in uses calibrated scales, a published time and tolerance, identity and licence checks, and a clear record of each weight against the class limit. At KBN events, officials scan the fighter's licence QR and record the weight in the referee app, which marks pass or fail.

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The weigh-in is where fairness and safety meet. Done badly, it produces disputes, mismatches and dehydrated fighters. Done well, it is quick, calm and uncontroversial. This guide covers the practical steps.

Before the day

  • Publish the weigh-in time, place and procedure in advance, including any tolerance.
  • Use calibrated scales, ideally certified, and a spare.
  • Place scales on a hard, level floor.
  • Prepare a list of bouts with each fighter's contracted weight class and limit.
  • Arrange a private area where appropriate, with respect for all athletes.

The sanction checklist asks for a weigh-in plan covering time, scales and tolerance.

Identity and licence

Every fighter should present an identity document and their licence. At KBN events, officials scan the QR code on the fighter's licence with the referee app, which shows:

  • Licence status (active, suspended, expired).
  • Medical clearance validity.
  • Suspension status, including medical suspensions.
  • The weigh-in entry.

Check-in with the QR code โ†’

Recording the weight

Record the weight exactly as shown on the scales, in kilograms. In the KBN app, the weight is compared with the class limit and marked pass or fail. Record a second attempt separately if the rules allow one.

Example weigh-in record (sample men's limits)
FighterClassLimitWeightResult
Fighter AWelterweight71.0 kg70.6 kgPass
Fighter BWelterweight71.0 kg71.4 kgFail (first attempt)
Fighter B, second attemptWelterweight71.0 kg70.9 kgPass
Illustrative. Tolerance and re-weigh rules are set by the event.

Missed weight

The event's rules decide what happens: a re-weigh within a time window, a financial penalty, the bout going ahead at a catchweight with the opponent's agreement, or cancellation. Apply the rules consistently and record the decision.

Never encourage dangerous last-minute weight loss. If a fighter looks unwell, involve the doctor. Officials must refuse a bout where medical or welfare standards are not met.

Hydration and welfare

Some organisations use hydration testing or same-day checks to discourage extreme dehydration. KBN's Medical Commission may set weight-cut limits and minimum rest periods. Whatever the rules, the doctor's assessment on fight day overrides a successful weigh-in.

Weight cutting safely โ†’

Minors

Young athletes should weigh in with a parent, guardian or designated adult present, with privacy respected. Safeguarding rules apply throughout.

A weigh-in running order

  • Officials arrive early; scales calibrated and checked with a reference weight.
  • Fighters queue by bout order; identity and licence checked.
  • Each fighter weighs in; the weight is recorded in the app and on paper.
  • Fighters who miss weight are told the re-weigh time, if any.
  • The supervising official signs off the weigh-in record.
  • Any concerns about a fighter's condition are passed to the doctor.

Transparency

Publish weigh-in results where appropriate. Fans, coaches and opponents trust events that record weights clearly and apply the rules consistently.

Myths and facts

Weigh-in myths
MythFact
Making weight means the fighter is fit to competeThe doctor's fight-day assessment overrides the scale
Scales do not need checkingCalibrate and check with a reference weight
Tolerance can be decided on the dayPublish it in advance and apply it consistently
Minors weigh in like adultsA parent, guardian or designated adult should be present, with privacy respected

Tournament weigh-ins

Multi-day tournaments often use a single official weigh-in before the first bout and, in some formats, daily checks. Whatever the rules, publish them in advance, apply them consistently and record every weigh-in in the same way.

Recording in the KBN app

At KBN events, the weight is recorded against the fighter's licence after scanning the QR code, and the app marks pass or fail against the class limit. That record is available to officials on the night and to administrators verifying the result later.

Accessibility and dignity

Weigh-ins can be stressful. Keep them orderly, respect privacy, avoid unnecessary crowds and cameras for athletes who prefer them, and make arrangements that respect all athletes' needs.

Frequently asked questions

QShould weights be recorded to one decimal place?
A

Record what the scales show. One decimal place in kilograms is common.

QWhat if the scales disagree?
A

Use the official, calibrated scale announced in advance. Have a spare and check calibration before starting.

QCan a fighter who missed weight still fight?
A

The event rules decide. Any decision must be applied consistently and recorded.

QDoes missing weight affect ranking points?
A

The ranking counts the verified official result in the division recorded for the bout. The event decides whether and how the bout goes ahead.

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