Go up. Size on the chest, and if the chest measurement sits right on the line between two sizes, the bigger one is the safer bet.
It's worth measuring a second time first, snugly around the deepest part of the chest just behind the front legs, and checking the numbers against our size chart. If the chest and length point to different sizes, go with the chest.
One thing to watch: an older tee that has relaxed with wear isn't a reliable guide to what to order next. Measure the dog, not the tee.
Sweaters are cut about 5 cm (2 in) roomier for layering, so a hound right on the border can end up a size apart in a sweater versus a Tweater. If that sounds like yours, email aroo@houndtees.com.au with the measurements and we'll help you choose.

New arrivals
Sale
New arrivals
Sale
New arrivals
Sale