# HP to Amps Conversion Calculator [3 Phase, Single, Two Phase, DC] | Horsepower to Amperes

HP to Amps calculator is used to calculate the amperes from horsepower of the motor is known. You can use the Electrical calculator to find the current in single, 2, and 3 phase motor circuits as well as in dc circuits.

Formulas: ## DC (Direct current) Calculations

In DC circuits amps is the ratio between the product of HP * 746 to Voltage times efficiency.

Mathematically:

DC Amps = [HP * 746] / [E * %age Efficiency]

Example: Find the current passing through 24 volt, 1/2 HP motor having an efficiency of 95%.

Solution: Current = [0.5 * 746] / [24 volt * 0.95] = 16.35 Amps

## Single phase AC Calculations

The single phase AC calculations involve the power factor in denomatior of equation.

Mathematical formula:

Single phase Amps = [HP * 746] / [E * %age Efficiency * PF]

Example: Determine the amps in single phase 1 HP, 120-volt motor having an efficiency rating of 88% operating at a power factor 0.9.

Solution: Current = [1 * 746] / [120 * 0.88 * 0.9] = 7.84 Amps

## Two Phase, 4 Wire AC Calculations

The two phase calculations are similar to 1 phase with an additional factor 2 in the denominators.

Mathematical equation:

Two-phase Amps = [HP * 746] / [E * %age Efficiency * PF * 2]

Example: Determine the current flowing through a two-phase, 0.5 HP, 220 volt motor having an efficiency rating of 90% and a power factor of 0.92.

Solution: Current = [0.5 * 746] / [220 * 0.88 * 0.9 * 2] = 1.07 Amps

## Three phase AC

The three-phase ac amps involve HP * 746 in the numerator and 1.73 times PF * Efficiency times voltages in the denominator. The formula is identical to the previous case with the difference of factor 1.73 instead of 2 in the denominator.

Mathematical equation:

Three phase Amps =  [HP * 746] / [E * %age Efficiency * PF * 1.73]

Example: Determine the current flowing through a three-phase, 2 HP, 400-volt motor having an efficiency rating of 93% and a power factor of 0.9.

Solution: Current = [2 * 746] / [400 * 0.93 * 0.9 * 1.732] = 2.57 Amps