Electrical Power Calculator

Electrical Power is evaluated from Voltage, Current and Resistance. The calculation reports Power, Power and Power.

Results

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About the Electrical Power Calculator

Electrical Power is treated here as a quantitative relation between Voltage, Current and Resistance and Power, Power, Power and Power.

The calculator uses a multi formula configuration. Each reported value is read as a direct evaluation of the stored rules with the declared field formats and units.

Formula basis:
P = V x I (Voltage x Current)
P = I^2 x R (Current^2 x Resistance)
P = V^2 / R (Voltage^2 / Resistance)
kW = W / 1,000
BTU/hr = W x 3.41214
hp = W / 745.7

Interpret the outputs in the order shown by the result fields. Optional inputs affect only the outputs that depend on those variables.

Formula & How It Works

The calculation applies the following relations exactly as recorded in the metadata:

P = V x I (Voltage x Current)
P = I^2 x R (Current^2 x Resistance)
P = V^2 / R (Voltage^2 / Resistance)
kW = W / 1,000
BTU/hr = W x 3.41214
hp = W / 745.7

Each output field is produced by substituting the supplied inputs into the relevant relation and then applying the declared rounding or text format.

Worked Examples

Example 1: Central Air Conditioner

Inputs

voltage: 240 current: 20
Power: 4,800 W. Power: 4.8 kW. Power: 16,378.27 BTU/hr. Power: 6.4369 hp

With Voltage = 240 and Current = 20 as the stated inputs, the result is Power = 4,800 W, Power = 4.8 kW and Power = 16,378.27 BTU/hr. Each value corresponds to the declared output fields.

Example 2: Electric Vehicle Charging

Inputs

voltage: 240 current: 32
Power: 7,680 W. Power: 7.68 kW. Power: 26,205.24 BTU/hr. Power: 10.299 hp

With Voltage = 240 and Current = 32 as the stated inputs, the result is Power = 7,680 W, Power = 7.68 kW and Power = 26,205.24 BTU/hr. Each value corresponds to the declared output fields.

Example 3: Speaker Amplifier Power

Inputs

current: 2.83 resistance: 8
Power: 64.071 W. Power: 0.06407 kW. Power: 218.62 BTU/hr. Power: 0.0859 hp

With Current = 2.83 and Resistance = 8 as the stated inputs, the result is Power = 64.071 W, Power = 0.06407 kW and Power = 218.62 BTU/hr. Each value corresponds to the declared output fields.

Example 4: Heating Element Resistance Check

Inputs

voltage: 120 resistance: 14.4
Power: 1,000 W. Power: 1 kW. Power: 3,412.14 BTU/hr. Power: 1.341 hp

With Voltage = 120 and Resistance = 14.4 as the stated inputs, the result is Power = 1,000 W, Power = 1 kW and Power = 3,412.14 BTU/hr. Each value corresponds to the declared output fields.

Common Use Cases

  • Calculate monthly electricity cost of an appliance
  • Find power consumption from voltage and current readings
  • Convert watts to BTU/hr for HVAC sizing