When one gets this big guessing size is the best you can do, unless he casually walks by (not unheard of).
At some point the nose to eye calculation isn’t enough. First, an Alligators tail is about half his body length. Usually that’s under water. However the width of their head, and size of their jowls gives a hint to their overall ‘bulk’.
It’s really not all about length, a big Alligator is just darn chunky 😆. They grow slow after the first 4, 5 years. It takes time to be this big and an Alligator can live for 50, 60 years.
Best to respect your elders.

Granddaddy of the swamp 😎
I’ve also noticed how the older gators lose the sharp definition of their head shape – you no longer see the sharp outlines of nose ridge, eyebrow ridges, and nostril ridges, for example. Compare this shot to your “Swimming Softly, Alligator” shots.
I call it by the technical term… fat head