New Balance Size chart

EU 36 37 37.5 38 38.5 39.5 40 40.5
CM 22 22.5 23 23.5 24 24.5 25 25.5
US - But 4 4.5 5 5.5 6 6.5 7 7.5
US - Women 5.5 6 6.5 7 7.5 8 8.5 9

EU 41.5 42 42.5 43 44 44.5 45 45.5
CM 26 26.5 27 27.5 28 28.5 29 29.5
US - But 8 8.5 9 9.5 10 10.5 11 11.5
US - Women 9.5 10 10.5 11 11.5 12 12.5 13

EU 46.5 47 47.5 47.5
CM 30 30.5 31 32
US - But 12 12.5 13 14
US - Women 13.5 14 15 -

The size guide is taken directly from New Balance's own website and is approximate as different models may vary.