Brake Horsepower Calculator

Multiply flow rate (Q), differential head (DH), and specific gravity (SG), then divide by 3960 multiplied by efficiency (E) to calculate brake horsepower (BHP).

Contents

1
2 Formula:
3 Solved Calculations:
4 What is the Brake Horsepower Calculator?
5 Final Words

The Brake Horsepower (BHP) Calculator determines the power required to operate a pump, fan, or motor efficiently. BHP measures the actual output power, accounting for the mechanical and hydraulic loads.

It’s widely used in engineering applications for selecting and optimizing equipment. Calculating BHP helps ensure the system operates efficiently, prevents overloading, and enhances energy management.

Formula:

BHP = $(Q ∗ DH ∗ SG) / (3960 ∗ E)$

Variable	Description	Unit
BHP	Brake horsepower	Horsepower (HP)
Q	Flow rate	Gallons per minute (GPM)
DH	Differential head	Feet
SG	Specific gravity	Unitless
E	Efficiency of the pump or fan	Decimal (e.g., 0.85 for 85%)
3960	Constant for converting units	—

Solved Calculations:

Example 1: Calculating BHP for a Pump with $Q = 200 \, \text{GPM}$ , $DH = 50 \, \text{ft}$ , $SG = 1.0$ , $E = 0.85$

Step	Value	Explanation
Flow rate ( $Q$ )	200 GPM	Flow rate of the pump
Differential head ( $DH$ )	50 ft	Difference in head
Specific gravity ( $SG$ )	1.0	Water-specific gravity
Efficiency ( $E$ )	0.85	Pump efficiency
Formula: $BHP = (Q ∗ DH ∗ SG) / (3960 ∗ E)$	Substitute values: $(200 ∗ 50 ∗ 1.0) / (3960 ∗ 0.85)$	Plug into the formula
Calculation	$10,000 / 3366$	Multiply and divide
Result	2.97 HP	Brake horsepower required

Example 2: Calculating BHP for a Fan with $Q = 500 \, \text{GPM}$ , $DH = 75 \, \text{ft}$ , $SG = 1.2$ , $E = 0.90$

Step	Value	Explanation
Flow rate ( $Q$ )	500 GPM	Flow rate of the fan
Differential head ( $DH$ )	75 ft	Difference in head
Specific gravity ( $SG$ )	1.2	Adjusted for specific fluid
Efficiency ( $E$ )	0.90	Fan efficiency
Formula: $BHP = (Q ∗ DH ∗ SG) / (3960 ∗ E)$	Substitute values: $(500 ∗ 75 ∗ 1.2) / (3960 ∗ 0.90)$	Plug into the formula
Calculation	$45,000 / 3564$	Multiply and divide
Result	12.63 HP	Brake horsepower required

What is the Brake Horsepower Calculator?

The Brake Horsepower (BHP) Calculator is a practical tool. One can operate it for determining the effective power output of an engine or motor after accounting for energy losses due to friction and other resistive forces. This is a key measure of an engine’s performance, often used in applications like automotive engines, pumps, and fans.

By inputting parameters such as torque, rotational speed, or flow rate and head (for pumps), the calculator quickly computes the brake horsepower. It simplifies complex calculations and ensures accuracy in performance evaluations.

This makes it particularly valuable for engineers, mechanics, and performance enthusiasts who need to optimize systems or evaluate engine capacities.

The tool also assists in comparing BHP to other power measurements, such as wheel horsepower or electrical power, providing insights into efficiency and effectiveness across various systems.

Final Words

In essence, the Brake Horsepower Calculator offers a reliable way to measure and analyze power output, enhancing decision-making for performance optimization in engines and motors. Its precision and convenience make it an essential resource for professionals and enthusiasts alike.