Hopper's right……I write the numbers down with indelable felt tip h/marker pen in the cover……..
if ur old belt is intact u can measure the outside distance BUT be accurate…….
a lot of belt companies now only quote the inside measurement….they do have a table to compare……
I order loads'a belt's this way…..belts over here ( Frogland) reg cost 10 times the price compared with the UK…..
so for the money I order the next belt either side……BUT I do repair a lot of machinery / tractors etc and they get used up quite quickly…….
for example wanted a 4.5m belt for my ride on mower…..quoted price + Vat here was not less than €160…
UK cost for exactly the same belt (Optie belt, German I think) was £6,80 + Vat….bought 2 and the postage was less than a tenner…..nuff said……..