Men wedding ring

Later edit: my wedding ring is 7 mm.
The last thing a groom thinks about is his wedding ring. It's the poor cousin to his bride's spectacular diamond engagement ring. That said, the groom's wedding ring is the one indicator that this man has a gorgeous wife somewhere, possibly on his arm. The great news is that a groom and bride's wedding rings are the one item in a wedding that don't cost a fortune. In this article, GroomGroove.com covers what a man needs to know about the most important piece of jewelry he'll ever wear.
Cost of the Wedding Ring

A man's wedding rings will cost between approximately $100 (for titanium rings) to $2000 (for platinum with diamonds set in the ring), with most rings coming in around $600. The reason for the price range (albeit much less of a range than a woman's diamond engagement ring) is the material used to make the band, and whether diamonds are used.
Mens Wedding Rings Materials
A groom's wedding band will be made of platinum, white gold, yellow gold, titanium, stainless steel or, lead. (Just kidding on the lead bit). Platinum and white gold are, at present, the most popular materials.

White gold is an alloy of gold (ie. it is gold and silver or palladium). This is where the concept of Karat comes in. Karat is a measure of the purity of the material. An 18K gold ring has 75% pure gold (the element). The higher the karat, the softer the ring and the more easily it will get scratched and dented. Accordingly, 18K is considered the optimal karat (with pure gold coming in at 24 karats).

There are positives and negatives with each type of wedding ring material you purchase. In particular, each will show different wear and tear after some time. The photo above shows what you can expect after one year of wear from each of the popular wedding ring materials.
Width of the Wedding Ring

The width of a man's wedding ring is measured in millimeters. The smallest rings are 3 mm in width, whereas the largest rings are 8mm in width. Generally, men will purchase a ring that is on the larger side, tending towards 5-6 mm.

Style

Most younger generations of men choose simple wedding bands, and generally, have shied away from yellow gold in favor of 18k white gold or platinum. Some men have chosen rings that have a braid carved in them, or alternatively, some other edging that the manufacturer has set. Diamond-studded rings for men are definitely in the minority.

For additional comfort, grooms should consider purchasing a ring where the inside of the wedding ring is cambered or with rounded edges. Frankly, however, when a groom first wears a ring - any ring - it is likely to feel like a foreign object, with hard edges. Over time, rounded edges probably don't add much, especially since most of the time, you'll not even notice your ring. (You will, however, notice when your ring is not on your finger, as you reach to play with it. Read on to find out why this is the case.)
When to Buy the Wedding Band

Generally, a groom will buy his bride's diamond engagement ring separate from the wedding bands, as the bride and groom each have wedding bands, and may want to choreograph the look of their rings with matching wedding bands. Accordingly, the wedding bands should be purchased two months before the wedding (at the latest). This will allow for time to get it sized properly, and make any adjustments.
Ring Measurements

The diameter of the ring will be measured either by your jeweler, or if you are buying wedding rings online, all reputable online retailers have suggested wedding ring size guides that you can print out. And even if you are buying your ring online, jewelry stores will happily fit you for your ring (as they try to sell you on their product!)
Working Out

A note - men should take their ring off and put it in a safe place (and the same place) when going to the gym to work out. This is because dumbbells and barbells can easily scratch or dent ring materials. Don't leave it in the locker, but rather, put it in your bag. Countless husbands have had to admit to their wives that they lost their 18k white gold wedding ring at the gym.
Playing with Your Ring

One of the first things a groom will do upon wearing his ring for the first time as a husband, and not a groom, will be to play with it. Twisting it on his finger, many a groom will twist and turn at the ring when nervous, such as when the groom makes his wedding speech.
Your wedding band will be a constant reminder of your wife and the commitment you've made. Perhaps it's a reminder that you haven't bought flowers recently. Or that you should tell her that you love her everyday. Whatever it signifies to you, take some time to pick out a man's wedding ring you will be happy to wear.