Sizing guide

Size Matters – it does really!
To ensure you get the best fit possible we have provided a detailed size guide. All the measurements here refer to the actual measurements of each garment. Please note Jump the Gun clothing tends to be slim fit, so sizing up common, especially in shirts and trousers.
You’ll need a fabric tape measure, and body measurements are most accurate if taken with a minimum of clothing on. Often a good starting point is to lay your favourite shirt flat on a surface and use those numbers as your starting point.
If in doubt, do please call us up or contact us by email for a chat, we’ve had a lot of practice sizing people up!

Nearly all of our clothing is slim fitting or very slim fitting – we want what you buy to fit you.
So it’s worth spending a few minutes reading the sizing guide.


Again these are very slim fit. We would suggest that if the measurement around your buttocks/hips is more than 4 inches bigger than your waist you should think about a size up from usual and use a belt or braces. The thigh size is also much smaller than regular trousers. All inside leg length is 32″.

Shirt sizing
As we have mentioned in the shirt descriptions, all our shirts do come up very small and fitted.

Here are the measurements in inches of all our shirts, using the diagram as a guide: