Woodsmen help! dog-like animal size estimate by track size

I’m currently writing a piece of fiction. A werewolf story. Early on, our narrator finds a wolf track. I read a book several years ago that had a formula for estimating the weight of a dog (coyoye, wolf, fox) based on the size of the track. And there’s a character in the story who can do this. Does anyone here know the formula?

I do not know the exact formula, but I do know that the size and depth of the track can be equated to the size of the animal. A K9 track roughtly the size of my hand and fairly deep in moist ground would be a large/heavy animal.

A smaller track (say 2" in diameter) would mean a smaller animal. Age of track must be taken into effect as well. As wind and water can make tracks look much bigger than they really are.

Outdoor Action Guide to Animal Tracking

Use dog paw card