How to choose the correct size
The ForMyDogs size grid shows the dimensions of the dog, not the finished product.
How to choose the right size for your pet:
1 - identify the breed
2 - measure the length of the dog's back
3 - measure the breast volume
4 - check the size chart and compare the parameters you got with it.
The main parameter is the length of the back.
The chest girth is designed so that your dog could freely move.