Horsepower to kVA Calculator

How to Calculate kVA from Horsepower

Converting horsepower to kilovolt-amperes (kVA) is a common task in electrical engineering, especially when dealing with motor and generator specifications. This calculation involves understanding the relationship between mechanical power, electrical power, efficiency, and power factor. Our calculator simplifies this process, but it's important to understand the underlying principles.

Calculation Formula

The formula to calculate kVA from horsepower is:

\[kVA = \frac{HP \times 0.746}{\eta \times PF}\]

Where:

• kVA is the kilovolt-ampere rating
• HP is the horsepower
• 0.746 is the conversion factor from HP to kW
• η (eta) is the efficiency as a decimal
• PF is the power factor

Calculation Steps

1. Convert the given horsepower to kilowatts by multiplying by 0.746
2. Convert the efficiency percentage to a decimal (if given as a percentage)
3. Divide the kilowatt value by the product of efficiency and power factor
4. The result is the kVA rating

Example Calculation

Let's calculate the kVA rating for a 100 HP motor with 90% efficiency and a power factor of 0.85:

1. Convert horsepower to kilowatts: \[100 \text{ HP} \times 0.746 = 74.6 \text{ kW}\]
2. Convert efficiency to decimal: \[90\% = 0.90\]
3. Apply the formula: \[kVA = \frac{74.6}{0.90 \times 0.85} = 97.39 \text{ kVA}\]

Therefore, a 100 HP motor with 90% efficiency and a power factor of 0.85 has a kVA rating of approximately 97.39 kVA.

Calculation Visualization

This bar chart visually compares the input horsepower (100 HP) and the resulting kVA rating (97.39 kVA) from our example calculation. The height of each bar is proportional to its value, illustrating the relationship between horsepower and kVA in electrical systems.