Taper elbow to wrist gauntlet

I am knitting my own design for the first time! I need help designing the tapering of a short-finger men’s long gauntlet. I am using a 2.5 mm circular needle with Wool-ease light weight yarn. My gauge is 7.5 rows/inch and 6 stitches/inch. The length of my son’s forearm is 7 inches at the wrist and 10 inches 1 inch below the elbow crease. This is to be a fitted gauntlet using ribbed stitch pattern of knit 1, purl 1 for a very masculine gauntlet. I am using the magic-loop method and I knit continental style. Any help is appreciated.

Welcome to KnittingHelp!
Sounds like an interesting project. Do you mean that your son’s wrist measures 7 inches around and 10inches around at the elbow?
That would work out to 42sts and 60sts at your gauge. Like hats however, you should decrease that a bit so that the gauntlet hugs the forearm. Then take the measurement in length from wrist to elbow and figure out the distribution of increases using your row gauge. You’ll be increasing at each end of the row in all likelihood.

You’re right. The length of the gauntlet from elbow is 10 inches long and his wrist circumference is 7 inches and elbow circumference is 10 inches. Yes, big, rugged young man.

Oh, I also did decrease the stitches a bit to 44 at the elbow and 36 at the wrist. I tried it on him and the 44 stitches so far is nicely snug and not tight or constricting.