I won't estimate the motor current in the way explained above. Motor's currents are not the simple Ohm's law calculation from the windings resistance. The current varies depending on the mechanical load applied to the motor, that is, how much force they are doing to move the load. Thats' why they get burnt when mechanically overloaded. Better to place an ammeter (your multimeter measuring current) in series with the motor and measure the real current with the motor working with its normal mechanical load. That's the normal current it will take from the power supply. Remember if the mechanical load increases it will take more current. I don't think the relationship between force and current is even linear by the way (I have to check). Therefore, careful with the calculations and estimates...