Gear & Sizing

Gi Shrinkage Calculator

Estimate how much your gi will shrink based on fabric, wash temperature and drying method — so you can either protect the fit you have or shrink a slightly-large gi on purpose.

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What actually shrinks a gi

Heat is the lever. Cotton fibres relax and contract when exposed to hot water and especially hot tumble-drying. A 100% cotton gi washed warm and tumble-dried hot can shrink several percent; the same gi washed cold and hung to dry will barely move. Pearl weave and other cotton weaves behave similarly; ripstop and pre-shrunk fabrics shrink far less.

This calculator turns those factors into an estimate. It can’t know your exact gi — manufacturing, prior washes and fabric blend all matter — so treat the output as a guide for how to wash, not a precise measurement.

Shrink on purpose, or protect the fit

If your gi is slightly too big, a deliberate hot wash and dry can bring it in. If it already fits, wash cold and hang dry to keep it there. Going the other way is much harder — you can’t reliably un-shrink a gi — so err toward caution with a gi you like.

Frequently asked questions

How do I shrink a BJJ gi?
Heat. Wash in warm or hot water and tumble dry on medium-high. Cotton gis respond most; pre-shrunk and ripstop gis move very little. Do it gradually and check the fit between cycles — you can’t easily reverse it.
How do I stop my gi from shrinking?
Wash in cold water and hang dry. Avoid hot tumble-drying entirely. This keeps cotton fibres from contracting and preserves the fit you bought.
Will a pre-shrunk gi still shrink?
Much less, but a little residual shrink is possible with high heat. If a gi is labelled pre-shrunk or ripstop, trust the size chart and wash it cool to be safe.