Judo weight classes

Seven categories for men, seven for women, and a rule almost no other combat sport has: judo does not only weigh you before the competition, it can weigh you again on the day and cap how much you put back.

The senior categories

Unlike boxing or wrestling, judo does not shorten its list for the Olympics. Every senior category is contested at the Games, which means the category you compete in domestically is the category you would compete in at the highest level there is.

The steps are 6 or 7 kg through the middle of the men's ladder and 5 or 6 through the women's. Tighter than wrestling, wider than amateur boxing.

The 5 per cent rule, and why it exists

This is the part that separates judo from the rest and it is not on any chart.

The official weigh-in happens the day before competition, which gives a night to recover. Every combat sport with a day-before weigh-in has that. What judo added is a check on the other end.

So the overnight refill has an upper bound. A judoka who arrives at 73.0 kg and returns to 80 has not been clever, he has been withdrawn.

Which changes the arithmetic of the whole descent. In a sport where the refill is uncapped, a fighter can strip water knowing he will put it back. Here the amount he is allowed to put back is fixed at 5 per cent, so anything he took off beyond that is simply gone from the body that competes.

What that means for choosing a category

The useful way to read the rule is backwards. Take your category limit, add 5 per cent, and that is the heaviest you are permitted to be on the mat.

The rules tables round some of these, so you may see 76.7 and 85.1 rather than 76.65 and 85.05. Work to the lower figure and the rounding never matters.

Now compare that ceiling with what you actually walk around at. If your ordinary weight is above the ceiling rather than merely above the limit, the category is wrong for you, and no weigh-in strategy fixes it.

Judoka who get this wrong tend to discover it in the same way: they make the scale comfortably, eat and drink normally overnight because that is what everybody does, and then find they have no room left if a check comes.

Junior, cadet and veteran

Juniors, under 21, use the senior list unchanged. Both sexes, all seven categories, same numbers.

Cadets, under 18, do not. They run eight, with an extra category at the light end where the field needs it:

Veterans use the senior list with age-band modifications.

Which group you fall into is decided by your age on 31 December of the competition year, not by your school year or your belt. So a judoka who turns 18 in November competes as a cadet only until that year ends, and the ladder under him changes on 1 January whether he is ready or not.

The 5 per cent check applies to cadets and juniors as well as seniors.

Weighing in, in practice

The overnight window is genuinely useful, and it needs running properly rather than by instinct. Fluid with sodium first, carbohydrate across the evening rather than all at once, and a familiar meal low in fat and fibre. How the refill actually works, and why plain water is the wrong first move.

Do not carry this rule into another sport

Judoka who also compete in grappling or in striking sometimes assume the percentage cap is normal. It is not.

Amateur boxing has no equivalent, because the daily weigh-in already does that job by a blunter route: the maximum comes back every morning you box, which caps the regain more completely than any percentage. Taekwondo runs its own version with no tolerance at all. Most professional formats cap nothing.

Do not carry the assumption in either direction if you compete in more than one of these. Every format side by side.

Before you commit to a category

• Take your weight on an ordinary Wednesday, mid-block, eating normally.
• Compare it with the competition-day ceiling above, not with the category limit.
• Work out the descent from there, at roughly half to 1 per cent of body mass a week.
• Confirm from the entry document which categories are being contested and, for age groups, which ladder applies.

And whatever the category, the days after a competition matter more than most judoka treat them. What the week after actually costs.

Judo gives you a night, and then takes back the option of using it fully. That is a more honest arrangement than most, and it rewards the athlete who chose the right category months earlier over the one who is good at scales.

Common questions

What are the judo weight classes?

IJF senior men compete at 60, 66, 73, 81, 90, 100 and over 100 kg. Senior women compete at 48, 52, 57, 63, 70, 78 and over 78 kg. All fourteen are contested at the Olympic Games, alongside a mixed team event.

How many weight classes are there in judo?

Seven for each sex at senior level, and juniors under 21 use the same seven. Cadets under 18 run eight, with an extra category at the light end: men from 50 kg and women from 40 kg. Veterans use the senior list with age-band modifications.

What is the 5 per cent rule in judo?

On the morning of competition a random weigh-in may be applied, and the athlete must be no more than 5 per cent above his category limit. For a 73 kg judoka that is 76.65 kg. It puts a ceiling on how much can be put back after the official weigh-in the day before.

When do you weigh in for judo?

The official weigh-in is the day before competition, which leaves a night to recover. A random check may then be applied on the morning of competition at 5 per cent above the category.

How much weight can a judoka put back after the weigh-in?

No more than 5 per cent of the category limit, if a random check is applied. That is the only refill cap of its kind in mainstream combat sport, and it means anything taken off beyond that margin is missing from the body that competes.