On Running Footwear Sizes

The Fit

Mondo Sizes: On running shoes use the Mondo sizing system, where each whole size is equivalent to exactly 1cm in length. To ensure the best fit we recommend:

If you have owned On before buy the same again; their sizing has not changed.
Shop using Mondo or US sizes.
Follow our "How to Measure Your Mondo Size" advice and video lower down this page.

US Sizes: On US sizes run true to size for a perfect fit right out of the box. No need to go up or down a size.

UK Sizes: On UK women's sizes run true to size for a perfect fit right out of the box. No need to go up or down a size. On UK men's sizes run half a size too small. If you want a UK size 10, buy an On UK 10.5 instead = Mondo 29. On have clearly made a mistake - there is no difference between men's and women's sizes in the UK. The correct UK size conversions from Mondo are shown in the "Absolute" column.

EU Sizes: On have clearly made a mistake - there is no difference between men's and women's sizes in the EU. The correct EU size conversions from Mondo are shown in the "Absolute" column.

On Our Website: On our website we use On sizes (even though they are not always correct) because these are what appear on the shoe boxes and the shoes themselves.

Mondo	US Men	US Women	UK Men	UK Women	EU Men	EU Women	UK (Absolute)	EU (Absolute)
22		5		3		36	3	35.3
22.5		5.5		3.5		36.5	3.5	36
23		6		4		37	4	36.7
23.5		6.5		4.5		37.5	4.5	37.3
24		7		5		38	5	38
24.5		7.5		5.5		38.5	5.5	38.7
25	7	8	6.5 *	6	40	39	6	39.3
25.5	7.5	8.5	7 *	6.5	40.5	40	6.5	40
26	8	9	7.5 *	7	41	41	7	40.7
26.5	8.5	9.5	8 *	7.5	42	41.5	7.5	41.3
27	9	10	8.5 *	8	42.5	42	8	42
27.5	9.5	10.5	9 *	8.5	43	42.5	8.5	42.7
28	10	11	9.5 *	9	44	43	9	43.3
28.5	10.5		10 *		44.5		9.5	44
29	11		10.5 *		45		10	44.7
29.5	11.5		11 *		46		10.5	45.3
30	12		11.5 *		47		11	46
30.5	12.5		12 *		47.5		11.5	46.7
31	13		12.5 *		48		12	47.3
31.5	13.5		13 *		49		12.5	48

How to Measure Your Foot Size

Snowboard boots are sized using the Mondopoint system which is very simple, making it nice and easy to choose the correct boot size. The Mondopoint size is the length of the inside of the boot liner, measured in cm.

To work out your size, the best way is to look it up on a pair of snowboard boots which fit you well but, if this is your first pair, measure the length of the insole on your best fitting pair of trainers. Remove the insole and measure, using a steal measuring tape, from the extreme tip of the toe to the extreme tip of the heel.

The measurement will always be exact to the nearest 0.5cm. You will never get 30.2 or 28.8; it will always be 30.0 exactly. This is your mondo shoe or boot size.

Still not sure what size to get? We're here to help!

Check out our Buying Guides for technical tips and tricks.

Try several and use our Low Cost 30 Day Returns.

Visit our Help Centre for advice from our team.