Back length is the distance along your dog's back from the base of the neck to the base of the tail. It is useful for products such as coats, but it is usually not the main measurement for choosing a dog harness. For most harnesses, chest girth matters more.
Where do you measure a dog's back length?
Let your dog stand naturally on all four paws. Place the start of the tape where the neck meets the shoulders and measure along the spine to the base of the tail. Follow the shape of the back without pulling the tape tight.
Why should your dog be standing?
Sitting, stretching or curling changes the shape of the back and can change the measurement. A relaxed standing position makes the result easier to compare with a size chart.
Do you need back length for a dog harness?
Usually not as the primary measurement. Harness sizing is commonly based on chest girth and sometimes neck measurements. Always follow the measurements listed for the specific harness rather than transferring a size from another brand.
How do you measure chest girth?
Measure around the widest part of the ribcage while your dog is standing. Keep the tape close to the body without squeezing. Our size guide shows the measurements used for UNBORINGBYPIP gear.
What if your dog is between sizes?
Do not automatically choose the larger size. Compare the full adjustment range and your dog's build. An oversized harness can rotate or shift, while one that is too small can restrict movement. Read how to recognise a harness that is too small and how to recognise one that is too big.
Which measurement matters most?
Use the measurement requested by the product's own size chart. Back length is useful when a product covers the back. Chest girth is usually more useful for a harness that sits around the torso.
Check the fit after measuring
Measurements help you choose a starting size, but the final check happens on your dog. The harness should stay stable while allowing normal movement. Continue with how tight a dog harness should be, how to put it on correctly or browse our dog harnesses.