The Gatsby Cat Harness Size & Measuring Guide

The Gatsby cat harness comes in three fully adjustable sizes - small, medium and large. Finding the right size Gatsby for your cat is easy. Just follow our simple steps below to measure your cat! 

You will need:

  • Your cat!
  • A cloth tape measure (or you can use a piece of string / ribbon / shoelace plus a flat ruler to measure against)
  • A pen and paper to write your measurements down

 Step 1: Take your cat's 'front' and 'back' measurements

With your tape measure, you're going to take two measurements on your cat, which we'll call 'front' and 'back'. All measurements should be made: 

  • While your cat is standing up
  • All the way around your cat 
  • With the tape measure drawn very snugly around your cat. Any fur underneath the tape measure should be well compressed!
How to measure your cat for their harness

1) Front: Measure from your cat's shoulderblades, around the front of their breastbone, and back again. Write this measurement down (in cm or inches). 

2) Back: Measure from your cat's shoulderblades, around the back of their legs, and back again. The tape measure should pass snugly behind their elbows. Write this measurement down (in cm or inches). 

 Step 2: Compare your cat's measurements to the size chart

Got your cat's 'front' and 'back' measurements written down? Perfect! Now simply compare those measurements to the chart below to find your cat's ideal size.

The Gatsby Cat Harness Size Chart

Harness Size

1. Front

2. Back

For kittens and petite adult cats 

25 - 32 cm

10 - 12.5 inches

28 - 36 cm

11 - 14 inches

For average adult cats

29 - 38 cm

11.5 - 15 inches

33 - 41 cm

13 - 16 inches

For extra large cats

37 - 46 cm

14.5 - 18 inches

41 - 50 cm

16 - 20 inches

If you need any help with measuring or sizing, simply send us an email at and we'll be happy to help! 

Measuring your cat later?

Enter your details to receive the Gatsby measuring guide as a handy PDF!

"We’ve discovered a harness that fits so well on our cats, Lumos & Noxie, that they can’t Houdini their way out of it. The Supakit Gatsby Harness."


"They are much easier to get on than our previous harness – they can just step into them and the single quick release buckle is easy to fasten and looks really stylish!"