Leash walking
How do I measure my dog for a harness?
Last updated 23 September 2026 · How we write and check this
Short answer
Measure around the widest part of the ribcage, just behind the front legs, and around the base of the neck, using a soft fabric tape measure rather than a rigid one for an accurate curve. Compare both numbers to the specific harness brand's sizing chart, since sizing is not standardized across manufacturers the way clothing sizes roughly are.
Taking accurate measurements
Have your dog stand naturally rather than sitting, and wrap the tape snugly but not tight around the ribcage, adding roughly 5 cm of ease for comfort. Repeat around the base of the neck where a collar would normally sit. Write both numbers down, since many harnesses require both measurements to select the right size.
Why brand specific charts matter
A medium size in one harness brand can fit very differently from a medium in another, so relying on your dog's weight alone often leads to a poor fit. Checking the actual chest and neck ranges listed for that specific product against your two measurements gives a far more reliable result.
Reweighing and remeasuring over time
Puppies should be remeasured roughly every 4 to 6 weeks during their fastest growth period, since a well fitted harness can become too small within a couple of months. Adult dogs are worth remeasuring after any noticeable weight change of a kilogram or more.
Key takeaways
- Measure both chest circumference and neck circumference with a soft fabric tape.
- Always check the specific brand's own sizing chart rather than relying on weight alone.
- Add roughly 5 cm of ease to the chest measurement for a comfortable, non restrictive fit.
- Remeasure growing puppies every 4 to 6 weeks and adults after any noticeable weight change.