*Measuring Your Dog for a Perfect Fit*1.Your baby usually wears size S doesnt mean all size S will fit him/her.Different designers and manufacturers use their own size charts. So the measurements given in a size SMALL by manufacturer "A" will be a size XS in manufacturer Bs size chart. Dont buy a particular size because that is what you always buy in a pet shop or online store. Always look at the size chart for chest girth and length and confirm the size before you commit to buy.2.If any of the measurements are between two sizes choose the larger size.If your measurements are toward the upper end of the range given for a particular size you may also want to choose the larger size as you may also wish to do for heavily coated dogs to accommodate all that fur.3.Take each measurement a bit loosely.Take each measurement a bit loosely so there will be room for your dog to move and breathe but not too loose. (the measurement for Belly Bands is the exception -- it needs to be a bit snug)Please measure carefully before buying and email us if you have any questions about fit before you bid or make a purchase.Size Details:XS: Neck: 24cm / 9.5inch Back: 23cm / 9inch Chest: 28cm / 11inch fit for small dogs or cats under 3.3poundsS: Neck: 28cm / 11inch Back: 27cm / 10.5inch Chest: 36cm / 14.2inch fit for 3.5-5.5 pounds small dogs or catsM: Neck: 35cm / 13.8inch Back: 32cm / 12.5inch Chest: 42cm / 16.5inch fit for 5.5-8.8 pounds small dogsL: Neck: 38cm / 15inch Back: 38cm / 15inch Chest: 45cm / 17.7inch fit for 8.8-13.2 pounds small dogsXL: Neck: 44cm / 17.3inch Back: 43cm / 17inch Chest: 49cm / 19.3inch fit for 13.2-16.7 pounds small dogs