ARGH! Using DTSwiss and http://www.wheelpro.co.uk/spokecalc/ I get completely different lengths spokes for a Pro II rear hub and XM819 rim.

DTSwiss = Le 245mm and Ri 244mm
Wheelpro = Le 259mm and Ri 258mm

Not even just a little bit out!

What am I doing wrong?

Thanks

wheelpro sounds right – do they do a 24″ 819 😉

LOL! That was my thought too!

I always use 3 different calculators, DT SWISS, Wheelpro and Edd
http://lenni.info/edd/
I then take the average from them….

I’ve become a Lenni after DT stopped listing other peoples kit.

I use the spoke calculator of sheldon browns site, it called spocclac. It seems spot on for easy wheel building. The web based ones seem to give different results for the same info. The differences are not big but they make a difference to how easy/quick the wheel builds. To get a difference that you have quoted the input info must be different. I also do not rely on other peoples measurements. I always measure my self three times to make sure.