I use my little spreadsheet. I can't access brainG online speedometer at the dragstrip. It works out pretty good for me. You enter your values into the yellow cells and everything else gets calculated.
6 KiloWatt A123 Racer
GTP-Pletty Big Maxximum+RX8. GTP-C50-6L Hacker+RX8. CRT.5-Pro4+ZTW esc.
24s2p EVG SX 49.6mph Ebike.
18s4p Raptor 60mph Ebike. 11.5KW