Finding the perfect fit is the secret to a happy, comfortable dog. As every breed is built differently, we highly recommend measuring your dog rather than guessing based on weight or breed alone. How to Measure: Use a soft tape measure (or a piece of string and a ruler). Measure the Neck: Aim for the base of the neck, just above the breastbone (this is lower than where a collar sits). Measure the Chest: Wrap the tape around the widest part of the ribcage, about 3-4cm behind the front legs. Check the Chest Length: Measure from the start of the breastbone (the manubrium) to 3-4 cm behind the front legs to find the best "Chest Length." Not sure which fit to choose? If your dog is between sizes or has a unique shape (like a very deep chest or a slender neck), we are here to help! Send your measurements and a photo of your dog to us using the Contact Us form or the Live Chat below, and we’ll give you a personalised recommendation. Our Fit Guarantee: If your purchase arrives and isn’t quite the perfect fit, don't worry! You are more than welcome to exchange it for a different size or fit profile. Please have a look at the Exchange & Returns section of this FAQ for the details.