Belt size for 184 lowboy

[Dieselrider]

Does anyone know off hand the fan belt size for a 184 lowboy? The part number in the parts book is 527 621 R1 but, they do not list a size there. This new (old) tractor is missing the belt. I can always remove the hood from my other and measure but, I thought one of you kind souls would have that information in your mind or handy. Thanks