Measure Your Dog for A Perfect Fit* Check photo gallery above to measure your dogs correctly* Your baby usually wears size S doesn't 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 B's size chart. Don't 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.* 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.* 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.Please measure carefully before buying and email us if you have any questions about fit before you bid or make a purchase.