How to measure your dog's head

Use the templates below to see if the Trident helmet will fit your dog. Print them all at once or try them one at a time. Please note that PDFs often auto scale to fit your paper size. You MUST make sure the templates print at 100% with NO PAGE SCALING.

For best results, cut out the templates and tape them onto cardboard to make them sturdy. Choose the best fit for each template type — W (width), L (length), S (snout). Use a tape measure for N (neck). 

All Trident Helmets include a Fit-Kit — a 10 piece set of Velcro backed spacer pads. These help snug up the fit for smaller heads. The setup can be altered later if needed. Simply change the spacer pads.

Cranial Length




Cranial Width





Snout Width


Neck Circumference


As you can see, there are many possible combinations. Be sure to take a decent photo of each best fitting template held in position on your dogs head. These will be helpful if you require our advice when setting up your helmet for a correct fit.

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College Station, Texas, USA

DUNS: 116944249

CAGE: 888X5

© 2021 K9 Helm Corp.

US Patent 10,045,513