Torque and horsepower formulas
Horsepower, torque, and RPM are tied together by the same relationship when torque is measured in lb-ft.
- Horsepower = torque x RPM / 5252
- Torque = horsepower x 5252 / RPM
- RPM = horsepower x 5252 / torque
Automotive Calculator
Torque Horsepower Calculator
Calculate torque, horsepower, or RPM from any two values when reading dyno sheets, engine builds, or powerband data.
Use any two engine values to calculate the third
Calculation mode
350.13
Torque result
Formulas
Torque = (horsepower × 5252) ÷ RPM
Horsepower = (torque × RPM) ÷ 5252
RPM = (horsepower × 5252) ÷ torque
Reference note
Torque and horsepower are numerically equal at 5252 RPM when torque is measured in lb-ft and power is measured in horsepower.
How to use the torque horsepower calculator
1
Choose whether you want to calculate torque, horsepower, or RPM.
2
Enter the two known values, such as horsepower and RPM or torque and RPM.
3
Review the calculated result and compare engine data points using the built-in formula reference.
Example engine checks
350 lb-ft at 4,500 RPM
299.9 HP
A quick dyno-sheet sanity check for one point on the power curve.
300 HP at 5,252 RPM
300 lb-ft
Torque and horsepower are numerically equal at 5,252 RPM.
250 HP and 300 lb-ft
4,376.7 RPM
Useful when reading a chart that gives power and torque but not engine speed.
Torque horsepower notes
- The 5252 constant applies to horsepower and lb-ft; metric torque units need a different constant.
- Peak horsepower and peak torque usually happen at different RPM points.
- This calculator checks relationships between numbers; it does not predict a full engine power curve.
Helpful for reading dyno and engine numbers
Useful for builds, tuning, and dyno sheets
Good when you want to check whether torque, horsepower, and RPM numbers line up without opening a spreadsheet.
Switch between three calculation modes
Move between horsepower to torque, torque to horsepower, and RPM checks in one place.
Uses the standard 5252 formula
Based on the common automotive relationship between torque, horsepower, and RPM for consistent reference checks.
Quick in the garage or on the go
Useful while reviewing build notes, dyno sheets, tuning changes, or engine specs from your phone or desktop.
Editorial and accuracy note
Torque Horsepower Calculator combines a working converter with practical guidance on the same page. The page is designed to show the formula, examples, rounding notes, and related tools so visitors can judge whether the result fits a task such as shipping, recipes, logs, design, travel, or automotive planning.
- Results are calculated in the browser with standard conversion factors for common units.
- For official forms, engineering tolerances, medical decisions, or compliance work, verify the original measurement and the relevant source rule.
- The surrounding notes focus on real use cases instead of repeating generic placeholder copy.
More automotive tools
Torque horsepower FAQ
What formula connects torque and horsepower?
Horsepower = (torque × RPM) ÷ 5252. Rearranging the same relationship lets you solve for torque or RPM when the other two values are known.
Why do torque and horsepower cross at 5252 RPM?
In lb-ft and horsepower units, the conversion constant makes torque and horsepower numerically equal at 5252 RPM.
Can I use this calculator on mobile?
Yes. The calculator works well on phones, tablets, and desktop screens.
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