How are single phase and three phase load amps and load kVA calculated?

Single phase Amps = (kVA x 1000)/Volts

Three phase Amps = (kVA x 1000)/Volts x 1.73

Single phase KVA = (Volts x Amps)/1000

Three phase KVA = (Volts x Amps x 1.73)/1000