Glove Size Converter

Hand circumference to numeric glove size, S/M/L and the EN ISO 21420 protective-glove sizes — built on the identity the whole scale rests on: the numeric size IS your palm girth in inches. Which also means you can check any glove chart in five seconds, and one published chart fails.

Last updated 24 Sep 2026

Glove sizes

Palm girth → size and letter

What have you got?Measure the DOMINANT hand — it is usually the larger. Wrap the tape round the fullest part of the palm just below the knuckles, leave the thumb outside the loop, and make a relaxed fist.

Hand circumferenceIn whatever unit the box above says. This is the measurement the whole numbering system is built on.

Letter size, if that is all you have

Hand length (mm), optionalMiddle fingertip to the wrist crease. It is a second dimension, not a size: use it to break a tie when the circumference lands between two numbers. Long narrow hands size up on length and down on girth.

Not a circuit: the measurement the whole numbering system is built on. The loop goes round the fullest part of the palm, just below the knuckle line, with the THUMB OUTSIDE it — that girth in inches IS your numeric glove size. The vertical dimension beside the hand is the hand length, fingertip to wrist crease, which is the second and independent row the standard carries. The ladder at the right is one inch per size from 4 to 13, to scale, with a box on yours.

203.0mmExample

a 203 mm hand circumference

The size is the girth, in inches

numeric size = hand circumference (in) = circumference (mm) ÷ 25.4 · standard’s mm column = round(size × 25.4) · hand length row ≈ 6 + (length mm − 160) ÷ 11

circumference: round the fullest part of the palm just below the knuckles, thumb outside the loop, relaxed fist, dominant hand
25.4 mm: one inch, and therefore exactly one numeric glove size. There is no other constant in the system
hand length: middle fingertip to wrist crease. A second dimension that steps about 11 mm per size, so it can disagree with the girth row
EN sizes 6–11: what EN ISO 21420 tabulates, 152 to 279 mm. Sizes 4, 5, 12 and 13 are manufacturers’ extensions

Worked example

a 203 mm hand circumference
203 mm ÷ 25.4 = 7.992 in, so the numeric size is 8 — the size IS the inches, and 203 is what 8 × 25.4 = 203.2 rounds to
Size 8 is the letter M in both manufacturers' charts checked
The standard pairs size 8 with a hand LENGTH of 182 mm; a longer hand at this girth points at a size 9 glove even though the palm does not
EN 420 required a glove of at least 240 mm total length at this size. EN ISO 21420, which replaced it in 2020, dropped that requirement — only welding and similar application standards still set one
Your hand is 0.0 mm off that row, which is under one per cent of a size step

The protective-glove sizes, and the identity behind them

Column four is the whole page. **The numeric glove size IS the hand circumference in inches**, and the standard’s millimetre column is that inch number rounded to the nearest millimetre — exactly, at every size from 5 to 11, and within a millimetre at the sizes manufacturers bolted on either end. The worst departure anywhere in the table is 0.047 in, or 0.36%. That is what lets you check any glove chart in five seconds: divide its millimetres by 25.4 and see whether you get the size number back. The hand-length column is a separate ladder stepping about 11 mm, not 25.4, so the last column falls steadily — which is why length is a tie-breaker and not a size. Sizes 6 to 11 are the standard’s own; 4, 5, 12 and 13 come from a manufacturer extending it.
Size	Letter	Hand circumference (mm)	… in inches	Minus the size number	Hand length (mm)	Min glove length under EN 420 (mm)	Length ÷ girth
4	3XS	101	3.976	-0.024	—	—	—
5	XXS	127	5.000	0.000	—	—	—
6	XS	152	5.984	-0.016	160	220	1.053
7	S	178	7.008	0.008	171	230	0.961
8	M	203	7.992	-0.008	182	240	0.897
9	L	229	9.016	0.016	192	250	0.838
10	XL	254	10.000	0.000	204	260	0.803
11	XXL	279	10.984	-0.016	215	270	0.771
12	3XL	304	11.969	-0.031	—	—	—
13	4XL	329	12.953	-0.047	—	—	—

A worked example of a chart that is wrong, and how the identity catches it

A published safety-glove chart that cites EN 420 puts XS = 6 at 178 mm and XXL = 11 at 305 mm. Every one of its circumferences is the standard’s value for the *next size up*, so the whole table is shifted one row. Nothing about it looks wrong until you apply the inch test in column six, where every row is a full size out. Buy from that chart and every glove arrives one size too big. This is not carried here to name and shame — it is carried because it is the commonest failure mode in glove charts and it is trivially detectable.
Size	Letter	Standard’s circumference (mm)	One retailer’s (mm)	That in inches	Minus the size number	Whose row it really is
6	XS	152	178	7.01	1.01	7
7	S	178	203	7.99	0.99	8
8	M	203	229	9.02	1.02	9
9	L	229	254	10.00	1.00	10
10	XL	254	279	10.98	0.98	11
11	XXL	279	305	12.01	1.01	12

What this page deliberately will not convert

Five refusals, all for the same reason: the quantity asked for is not the quantity the numbering system measures. The numeric scale works because it is an inch of palm girth; anything that is not that cannot be converted into it.
Asked for	Why not
Children’s glove sizes	No standard governs them and no source checked gave a hand-circumference table. Children’s gloves are sold by age, which is not a measurement. Measure the hand and read the numeric size off the table above — a child’s hand is usually below size 6, off the bottom of the protective range.
Boxing gloves	A boxing glove’s number is a WEIGHT in ounces — the mass of padding — not a hand measurement at all. A 16 oz glove is not a size 16 hand. Nothing on this page applies to them.
Disposable nitrile, latex and vinyl gloves	Letter sizes only, and the film stretches, so the bands overlap: one published guide says a Large “typically fits numeric sizes 9-10”. There is no defensible number to convert to.
Ski, motorcycle and gardening glove S/M/L	Brand convention with liners and insulation in the way. The girth measurement is still the right starting point, but the letter is the maker’s own and does not transfer.
Width fittings or “slim” sizes	Not a dimension either standard carries. Use the hand-length row above as a tie-break instead: a long hand at a given girth wants the longer glove, not the wider one.

The size is the inch — which makes every chart checkable

A numeric glove size is your hand circumference in inches. That is not a rule of thumb; it is the definition the scale was built on, and it survives in EN ISO 21420’s own numbers. The standard pairs size 6 with 152 mm, 7 with 178, 8 with 203, 9 with 229, 10 with 254 and 11 with 279 — and those are 6, 7, 8, 9, 10 and 11 inches rounded to the nearest millimetre. Across the whole table, including the sizes manufacturers added below 6 and above 11, the worst departure from the identity is four hundredths of an inch. So one size is one inch of palm girth, everywhere, and there is no second constant to learn.

That identity is also a test, and it is the most useful thing here. Take any glove chart, divide its millimetre column by 25.4, and see whether the size number comes back. One published safety-glove chart that cites EN 420 puts XS = 6 at 178 mm and XXL = 11 at 305: every circumference in it is the standard’s value for the next size up, so the whole table is shifted a row and everything ordered from it arrives a size too big. Nothing in the chart’s own presentation gives that away. The inch test does, in seconds.

How to measure. Wrap the tape round the fullest part of the palm, just below the knuckles, with the thumb left outside the loop, and make a relaxed fist so the hand is at working size rather than flat. Measure the dominant hand: for most people it is measurably the larger, and a glove sized to the smaller one binds on the other. Round to the nearest whole size; where a maker offers halves, the half size is still half an inch of girth and means what it says.

Hand length is a second dimension, and it can disagree with the first. The standard carries a length column too — 160 mm at size 6 up to 215 at size 11 — and it steps about 11 mm per size where girth steps 25.4. So the ratio of length to girth falls steadily across the range, from about 1.05 at the small end to 0.77 at the large, and a hand that is long and narrow lands on a higher length row than girth row. For a glove with fixed finger lengths that is the difference between fitting and pressing at the fingertips, and empty fingertips are worse than tight ones around machinery. This page works out both rows and tells you when they differ.

What has changed in the standard, and what this page refuses. EN ISO 21420:2020 replaced EN 420:2003+A1:2009 and dropped EN 420’s minimum glove length table; the 220 to 270 mm figures still printed on manufacturers’ charts are the old requirement, and only application standards such as welding now set a minimum length. Both documents are copyrighted and nothing is reproduced from either — the size and circumference pairs here were read from two manufacturers’ published charts that attribute them to the standard and that agree at every shared row. Four things this page will not do: children’s glove sizes (sold by age, which is not a measurement), boxing gloves (the number is the mass of the padding in ounces), disposable nitrile and latex (letters over a stretchy film, with one published guide putting a Large across sizes 9 to 10) and width fittings, which neither standard carries. For the other body scales built on a single girth measurement see the hat size converter and the ring size converter.

Frequently asked questions

Is a glove size really just my hand measurement in inches?

Yes, and that is why the numeric scale exists. Wrap a tape round the fullest part of your palm below the knuckles with the thumb outside the loop: the number of inches is your glove size. The check is exact — EN ISO 21420’s own millimetre column (152, 178, 203, 229, 254, 279 for sizes 6 to 11) is that inch number rounded to the nearest millimetre, and the worst departure across the whole table is four hundredths of an inch.

Which hand should I measure?

The dominant one. For most people it is measurably the larger, and a glove that fits the smaller hand will be tight on the other. If you land between two sizes, size up for anything you have to grip in for long, and use the hand-length row above to decide: a long hand wants the longer glove even if the girth says otherwise.

What is a size 8 glove in S/M/L?

A medium, in both manufacturers’ charts cross-checked here: 6 = XS, 7 = S, 8 = M, 9 = L, 10 = XL, 11 = XXL, with 4, 5, 12 and 13 extending to 3XS and 4XL. But treat a letter as a label on a number, not as a size in itself — letters have no definition and disposable gloves use them completely differently.

How do I tell whether a glove chart is right?

Divide its millimetre column by 25.4 and see if you get the size number back. One published chart that cites EN 420 puts XS = 6 at 178 mm; 178 ÷ 25.4 is 7.0, so its whole table is shifted a row and every glove ordered from it arrives a size too big. That five-second test is the most useful thing on this page.

Does hand length matter?

It matters when the two measurements disagree. The standard carries a length column as well as a girth column, and it steps about 11 mm per size where girth steps 25.4 — so the ratio of length to girth falls steadily across the range, from about 1.05 at size 6 to 0.77 at size 11. A hand that is long and narrow sits on a higher length row than girth row. For a glove with fixed finger lengths, that is the difference between fitting and binding at the fingertips.

What does EN ISO 21420 actually require?

It is the general requirements standard for protective gloves, and sizing is one clause of it: sizes are set against hand circumference and hand length, and a glove must be marked with its size. It replaced EN 420:2003+A1:2009 in 2020 and dropped EN 420’s minimum glove length table — the 220 to 270 mm figures in the table above are EN 420’s, kept here because manufacturers’ charts still print them. Application standards such as welding still set their own minimum lengths. Both documents are copyrighted; nothing is reproduced from either here.

Why won’t this page size boxing gloves or disposables?

Because neither number is a hand measurement. A boxing glove’s ounces are the mass of its padding — a 16 oz glove says nothing about the hand inside it. Disposable nitrile and latex gloves are sold in letters only and the film stretches enough that one published guide puts a Large across numeric sizes 9 to 10. There is no defensible conversion, so none is offered.

Related calculators

References

EN ISO 21420:2020, Protective gloves — General requirements and test methods, and EN 420:2003+A1:2009, the withdrawn predecessor it replaced. Both are copyrighted and neither was fetched; no table from either is reproduced here. They are cited by number because they are what fixes a numbered glove size to a hand measurement.
SHOWA, Hand Sizing Chart (showagroup.com, read 27 September 2026), which cites EN 420 and gives sizes 6 to 11 against hand circumferences of 152, 178, 203, 229, 254 and 279 mm, hand lengths of 160 to 215 mm, and the minimum glove lengths 220 to 270 mm that EN 420 required.
Wenaas, EN ISO 21420 — General requirements and test methods (wenaas.com, read 27 September 2026), the independent check. It cites EN ISO 21420:2020, agrees with SHOWA at every shared size, extends the ladder to sizes 4, 5, 12 and 13 (101, 127, 304 and 329 mm) and gives the letter equivalents 3XS to 4XL. It also records what changed: “The EN ISO 21420 standard does not specify minimum lengths for gloves, but certain application-specific standards, such as in welding, require a defined minimum glove length.”
WC Safety, Glove Size Chart (wcsafety.com, read 27 September 2026), used here for its measuring instruction — “Wrap the tape around the fullest part of your palm, just below the knuckles, leaving the thumb out”, on the dominant hand, with hand length as “a tiebreaker when circumference falls between sizes” — and as a worked counter-example. Its own chart, which also cites EN 420, prints XS = 6 at 178 mm and XXL = 11 at 305 mm: every circumference is the standard’s value for the next size up, which the inch test on this page catches immediately.

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