A ring that's the wrong size either spins around your finger all day or won't clear the knuckle going on. Both are sizing problems, not quality problems, and both are avoidable with a five-minute check before you order.
Wrap a strip of paper or string around the base of the finger you're sizing for, where the ring will actually sit. Mark where it overlaps, then measure that length with a ruler. Compare that number against a standard ring size chart to get your size.
Measure at the right time of day. Fingers swell slightly in heat and shrink in cold, so measure in the evening when your hand is at its normal size, not right after a workout or first thing in the morning.
Account for the knuckle. If your knuckle is noticeably wider than the base of your finger, size for the knuckle, not the base — a ring that fits the base perfectly but won't pass the knuckle is unwearable. Some people need a size up specifically for wide bands, since a broader band feels tighter than a thin one at the same size.
If you're buying for someone else and can't measure their finger directly, borrow a ring they already wear on the intended finger and trace the inside diameter, rather than guessing from hand size — hand size and finger circumference don't track together the way people expect.
The same hallmark and weight checks from our silver purity guide apply to rings too — a hollow band will dent and warp under normal wear.
Browse the current ring and earring sets once you've got the right size.