Guys size up on gloves because they think a tighter fit is going to be uncomfortable. Then they spend the next six months losing the glove off their hand whenever they pick up something small, fumbling fasteners, and burning through cut-resistant gloves twice as fast.
A correctly-fitted glove has the seam at the tip of your fingers — not past it. The cuff sits at your wrist with no slack. When you make a fist, there's no excess fabric bunching at the palm. When you flex your fingers individually, the glove flexes with them, not after them.
When the glove is too big, three things go wrong. First, you lose dexterity at the fingertips. The empty space in the finger means the glove rotates around your finger before the glove tip catches whatever you're trying to pick up. Small fasteners, screws, electrical wire — all twice as hard.
Second, the cut-resistance rating drops. A cut-resistant glove is rated assuming the fabric is in contact with your skin where the cut would happen. If the glove is loose, the blade can catch the loose fabric, slide it across your hand, and the rated layer ends up somewhere other than where the cut is. ANSI A4 fabric only protects you if it's between the blade and you.
Third, the glove wears through faster. Loose gloves slide on your hand with every motion. That sliding wears the inside of the glove against your skin and wears the outside against your tools. A glove that fits doesn't slide. It moves with you.
Sizing is usually number-based — 7, 8, 9, 10, 11 — or letter-based — S, M, L, XL. Measure around your dominant hand at the knuckles, not including the thumb. The number in inches is roughly your glove size. Most adults are 9 or 10. If you're between two sizes, go down, not up.
We have most brands in stock in the standard sizes. Try them on at the counter. If the glove falls off when you make a fist and shake, it's too big.