The judo weigh-in is the step before any competition run by weight category. Each judoka stands on an official scale in underwear and must be at or under the category limit. On the international circuit, the official weigh-in takes place the day before, then a random weigh-in on competition morning checks that athletes are no more than 5% above their limit. At national and local level, the timing and rules depend on the event.
People underestimate this moment. In youth judo, more competitions are lost on the scale than on the mat.
How an official weigh-in works
Judoka report during a time slot announced by the organizer. Officials check identity, membership or license card, and the category entered. Men and women weigh in separately, with officials of the same sex.
You step onto the official scale. The number shown is final. At many events, you get one or more attempts within the slot if you are over, which gives time to change or use the toilet. The number of attempts and the length of the slot are set in the event rules.
A training scale never quite matches the official one. Leave a margin.
| Item | What to know |
|---|---|
| Timing | Day before or same morning, depending on level |
| Clothing | Underwear, no judogi |
| Documents | License, membership card or ID, depending on the event |
| Attempts | Set by the event rules |
| Missed weight | No fight in that category |
For the limits of each category, see our guide to judo weight categories.
Day-before weigh-in and the random weigh-in
On the IJF circuit, the official weigh-in happens the evening before competition. That leaves a night to rehydrate and eat. To limit abuse, the IJF added a random weigh-in on the day: a few judoka per category are drawn and weighed again before their first match. Their weight must not be more than 5% over the category limit.
A concrete example: in the under 73 kg category, 5% is a little over 3.6 kg. A judoka who weighs 73 kg the night before and 77 kg the next morning would be over the tolerance.
The rule targets a real problem. Some athletes were dropping several kilos of water before weigh-in and putting it back on overnight. The random weigh-in does not end the practice, but it limits it.
National and local events
Youth competitions and many regional events weigh in on the same morning, a few hours before the first matches. National championships follow their own rules, published by the federation each season. Always read the invitation: time, place of weigh-in and documents required.
With children, organization is often more flexible. Some events adjust pools after the weigh-in to make groups of similar weight. The exact rules vary between federations and organizers.
Making weight safely
We will not give a method to lose weight fast. Rapid weight loss through dehydration, saunas or plastic suits is dangerous. It hurts performance, raises the injury risk and can have serious health consequences. For a growing teenager, it is completely off the table.
Here is what we recommend instead.
- Pick a realistic category. Your fighting weight is the one you make without a last-minute diet. If you need to lose more than a few hundred grams in competition week, the category is probably wrong.
- Weigh yourself regularly, at the same time of day, in the weeks before. Not every day with anxiety. Just enough to know how your weight moves.
- Keep your usual eating habits the day before. No new food, simple and sufficient meals, water.
- After weigh-in, eat and drink normally, without overdoing it. Practical ideas are in our article on what judoka should eat before competition.
For weight loss over the long term, read our page on cutting weight for judo, and work with a doctor or a dietitian. For any health question, see a doctor.
Weigh-in as part of your preparation
The weigh-in is part of the competition, just like the warm-up. Pack your bag the night before: license or ID, spare underwear, a water bottle and something to eat afterwards. The full list is in our competition bag checklist. If it is your first event, our guide to preparing your first judo competition covers the rest of the day.
For the wider rulebook, from scores to penalties, see our guide to judo rules.
One last tip, for coaches. Weigh your competitors at training a week before the event, at the same time of day as the official weigh-in. This simple check avoids most bad surprises, and it defuses the panic diets that teenagers invent on their own.