How this instrument works
Glove sizing is unusually well standardized compared to most of the sizing conventions on this site. EN 420, 'General requirements for protective gloves,' is a genuine formal European Norm that defines glove sizing directly: the numeric glove size is simply the hand circumference measured in inches around the palm at its widest point, excluding the thumb. A 9-inch hand circumference is glove size 9, full stop — there's no offset, scaling factor, or brand-specific chart involved in the core numbering.
That direct 1:1 relationship is why this calculator's formula is just the measurement itself, passed straight through. The letter sizes you see on retail packaging — S, M, L, XL, and so on — are a convenience layer added on top of the EN 420 numeric scale, typically grouping adjacent numeric sizes: size 9 commonly sits in the Medium/Large band, size 7.5 in Small, and size 11 in XX-Large, though the exact letter cutoffs vary a little between manufacturers even though the underlying numeric standard doesn't.
Because EN 420 is a genuine standards-body specification rather than an informal trade convention, this calculator's core sizing figure carries more confidence than most sizing tools on this site — the same can't be said for the exact inch-to-letter mapping, which is common practice rather than something the standard itself fixes rigidly. Gloves are typically sold in half-size increments, which is why the calculator also rounds your exact measurement to the nearest half size a retailer is likely to stock.
- Wrap a flexible tape measure around your dominant hand at its widest point, just below the knuckles, not including the thumb.
- Keep the tape snug against the skin without pulling it tight, and read the circumference in inches.
- Enter that figure into Hand circumference (inches).
- Read Glove size — the EN 420 numeric size, equal to your hand circumference directly.
- Read Glove size (nearest half size) for the figure most glove retailers actually stock and sell against.
Worked example — a 9-inch hand, a common Medium/Large glove
A hand circumference of 9 inches, measured snugly around the palm below the knuckles, gives a glove size of exactly 9.0 under EN 420's direct hand-circumference-equals-size rule — no rounding or offset needed since it's already a whole number.
That size 9 sits in the Medium/Large band on most manufacturers' letter-size charts. By comparison, a smaller 7.5-inch hand comes out to glove size 7.5 (typically labeled Small), and a larger 11-inch hand comes out to glove size 11 (typically XX-Large) — the numeric scale runs in a straight, evenly spaced line from small hands to large ones, which is exactly what a standards-body specification is meant to guarantee.
Questions
Is glove sizing actually based on a real standard, or just a trade convention?
It's a genuine formal standard — EN 420, 'General requirements for protective gloves,' is a European Norm published through the CEN standards process, and it explicitly ties numeric glove size to hand circumference in inches. That puts it on firmer ground than most sizing conventions (shoe, ring, hat, and belt sizes on this site are all informal trade practices with no comparable standards-body backing). Note that EN 420 has since been technically superseded by the newer EN ISO 21420:2019, though the hand-circumference-to-size relationship this calculator uses carries over.
How exactly should I measure my hand for glove sizing?
Wrap a flexible tape measure around your dominant hand at its widest point, which is usually just below the knuckles across the palm, keeping the thumb out of the loop. Hold the tape snug against the skin but not pulled tight, and read the circumference in inches — that number is your EN 420 glove size directly, with no conversion needed.
Why do glove sizes come out as numbers like 7.5 or 9, not just S/M/L?
The numeric size is the actual EN 420 standard measurement — hand circumference in inches — while letter sizes (S, M, L, XL) are a simplified retail convenience layered on top by individual manufacturers, and the exact number-to-letter cutoffs vary slightly between brands. Using the numeric size directly, as this calculator does, gives you a more precise and standard-consistent starting point than relying on letter sizing alone, especially when comparing gloves across different manufacturers.
Should I measure my dominant hand or both hands?
Measure your dominant hand, since most people's hands differ slightly in size and gloves are typically sold as a matched pair sized to fit the larger of the two comfortably. If the difference between your hands is noticeable, size to the larger measurement — a glove that's a touch loose on your non-dominant hand is far less of a problem than one that's tight on your dominant hand.
Does this sizing apply to all glove types — work gloves, gardening gloves, dress gloves?
EN 420's hand-circumference sizing is most directly used for protective and work gloves (the standard's actual scope), but the same numeric convention is widely borrowed across general glove retail, including gardening and casual gloves. Specialty categories like ski gloves, batting gloves, or dress gloves sometimes use their own sizing scales instead, so it's worth checking a specific product's size chart if it's not a general protective or work glove.