Size	Age	Height (in.)	Chest (in.)
X Small	6/7	119 - 129.5	61 - 66
Small	8/9	129.5 - 140	66 - 68.5
Medium	10/11	140 - 150	68.5 - 75
Large	12/13	150 - 160	75 - 78.5
X Large	14+	160 - 170	78.5 - 82.5

Size	Age	Height (in.)	Chest (in.)
X Small	6/7	47 - 51	24.5 - 26
Small	8/9	51 - 55	26 - 27
Medium	10/11	55 - 59	27 - 29.5
Large	12/13	59 - 63	29.5 - 31
X Large	14+	63 - 67	31 - 32.5

Our polos do have a slimmer fit. If you are in between sizes, we recommend sizing up.