Very cool, auto-conversion is really awesome, I think I found a bug though:
5 kg + 5 kg = 10 kg
but
5 kg + 6 kg = 11.000 kg
5 kg + 5 kg = 10 kg
but
5 kg + 6 kg = 11.000 kg
yeah that's not supposed to happen. I'm not completely sure what's up there but thanks for the report
km/h doesn't work but km/hour does. I haven't added h as an alias for hour since it's also the SI prefix for hecto.