A Calming Donut Dog Bed is designed to provide a sense of security and comfort for your pet. When choosing the right size, you want to make sure it's large enough for your dog to curl up and feel cozy but not so big that they lose the feeling of protection the bed is meant to provide.

Here's how you can measure your dog to determine the right size for a Calming Donut Dog Bed:

1. Measure the diameter of your pet while they are comfortably curled up. Starting from the back of their head, wrap the measuring tape or ruler around their body to the back of their rump. Make sure the tape is snug but not tight. Note down the measurement.
   
   
2. Add 15-20% to each measurement to allow for your dog to stretch out and move around.
   
   
3. Use the measurements you've taken to select the appropriate size of calming donut bed for your pet. Compare your measurements with the size options provided by the manufacturer. Generally, it's better to choose a slightly larger size if your pet's measurements fall between two sizes. This ensures they have enough space to curl up comfortably within the bed.