Horsepower Calculator
Calculate horsepower from torque and RPM, or explore the relationship between power and performance with our interactive graphs.
Calculate Horsepower
0 1000 lb-ft
500 10000 RPM
Horsepower Result
285.5 HP
Formula Explanation
Horsepower is calculated using the formula:
HP = (Torque × RPM) ÷ 5252
This formula is based on James Watt’s definition of horsepower, where 1 horsepower is equal to 550 foot-pounds per second.
Performance Visualization
Horsepower vs. RPM
Torque vs. RPM
Understanding the Graphs
These graphs show how horsepower and torque change with RPM for a typical performance engine. Notice how horsepower and torque curves intersect at 5252 RPM, which is consistent with the mathematical formula.
Power Unit Conversions
Foot-pounds/sec
209,825
BTUs/hour
727,260
Calories/sec
50.9
Watts
212,900
Horsepower Gauge
285.5 HP
Performance Classification
0-100 HP: Economy
100-200 HP: Standard
200-300 HP: Performance
300-400 HP: High Performance
400-500 HP: Sports Car
500+ HP: Supercar Territory
About the Gauge
This visual gauge shows where your calculated horsepower falls on the performance spectrum, from economy vehicles to supercars.