Don't know about 'standard' but mine are 38". High enough to see under, and low enough for good task lighting.

I had a fight with myself over this measurement also. I started out at 34" but it was just too low. I went up to 42 but our pendant has up lighting as well and it didn't spread enough on the ceiling. It ended up at 39" which has worked well for us. The angle of the light beam determines the light 'spread' on the counter and therefore influences the height.

Thank you! Mine are 27", too low obviously

Mine are 38" as well. That was the length of the chain, there was no extra included in package. But I have to say it is the absolute perfect height for me.