Simple Electrical Formulas

Steps In Calculating Usage Costs

1. Volt x Amps. = Watts

2. Watts/ 1000 = Kilowatt (kW)

3. Kilowatt (kW) x Hours Of Use = Kilowatt Hour (kWh)

4. Kilowatt Hours (kWh) x .06226 (rate)+ $13 (customer charge)= Cost Of Usage

Steps In Calculating VA (Volt/Amps) for UPS (Uninterruptible Power Supply) Systems

1. Total amperes of all equipment to be used on UPS.

(MMX PC's average 2.8 Amps. beginning 1997)
(PCs average 3.5 Amps. prior to 1997)

1a. If the equipment lists total watts only, use W x 1.4 to get VA

2. Total Amps. x 120 Volts = VA (Volt Amps.)

3. VA x 1.2 = Total VA

4. Choose the UPS that is rated higher than the Total VA

Calculating Watts

Volts x Amps. = (Watts)

Calculating Amperes

Watts/ Volts = (Amps)

Calculating Volts

Watts/ Amps. = (Volts)

Calculating Resistance (Ohms)

Volts/ Amps. = R (Resistance)