Model crank and wheel torque from peak engine data. Check crossover, averages, and drivetrain losses. Export clean tables for reports, tuning notes, and reviews.
| RPM | Torque (lb-ft) | Torque (Nm) | Horsepower |
|---|---|---|---|
| 1000 | 191.40 | 259.50 | 36.44 |
| 2500 | 275.10 | 372.98 | 130.94 |
| 4200 | 330.00 | 447.42 | 263.90 |
| 6500 | 258.56 | 350.56 | 320.00 |
| 7200 | 212.02 | 287.46 | 290.75 |
This sample uses 320 HP at 6500 RPM, 330 lb-ft at 4200 RPM, 15% drivetrain loss, 0.58 low-end factor, and 0.82 redline factor.
The core horsepower and torque relation is:
Horsepower = (Torque in lb-ft × RPM) / 5252
The reverse form is:
Torque in lb-ft = (Horsepower × 5252) / RPM
Torque in newton-meters is calculated with:
Torque in Nm = Torque in lb-ft × 1.3558179483
Wheel output is estimated with drivetrain loss:
Wheel Output = Crank Output × (1 − Drivetrain Loss Fraction)
This calculator builds an estimated torque curve from key anchor points. Those points include idle behavior, peak torque, the midpoint before peak power, peak power RPM, and redline drop-off. Linear interpolation fills the curve between anchor points.
This engine torque curve calculator helps estimate torque across the full RPM band. It starts with known peak horsepower and peak torque values. It also uses the RPM points for those peaks. From there, it builds a practical curve for engineering review. The tool also estimates wheel torque and wheel horsepower after drivetrain loss. That makes it useful for drivetrain planning, dyno preparation, and performance analysis.
A torque curve shows how strongly an engine pulls at different engine speeds. Peak numbers alone do not show the full picture. Two engines can share the same peak horsepower, yet feel very different on the road or track. A broad torque band usually improves drivability. A narrow high-RPM curve may favor racing use. Engineers, tuners, and builders often study torque shape when comparing cam profiles, turbo sizing, intake design, gearing, and shift strategy.
This calculator gives crank torque, crank power, wheel torque, and wheel power. It also shows anchor points used to estimate the curve. That makes the output easier to audit. The average values help when comparing combinations over a working RPM range. The crossover note highlights whether 5252 RPM is inside the analyzed band. This matters because torque and horsepower are numerically equal at 5252 RPM when torque is expressed in lb-ft.
Use this calculator as an estimation tool, not a dyno replacement. Real engines can gain or lose torque due to volumetric efficiency, boost control, ignition timing, fuel quality, exhaust tuning, and thermal limits. Still, a calculated curve is helpful during early design and planning. It can support gear ratio studies, traction estimates, and engine matching decisions. For the best accuracy, compare the generated table with measured dyno data and refine the shaping factors to match the real engine behavior.
It estimates an engine torque curve across the selected RPM band. It also calculates horsepower, wheel torque, and wheel horsepower using your drivetrain loss value.
No. It is an engineering estimate built from peak values and shaping factors. A real dyno test is still the best source for final validation.
That order matches most real engine behavior. Torque generally peaks first, then horsepower continues rising as RPM increases until airflow and efficiency start falling.
Drivetrain loss is the power absorbed by components between the crankshaft and the wheels. It includes gearbox, differential, shaft, and tire-related losses.
It shapes estimated torque near idle and early RPM. A higher factor creates a stronger low-speed torque value before the curve reaches peak torque.
It sets how sharply torque falls after the horsepower peak region. Lower values produce a steeper drop near redline. Higher values keep the top-end flatter.
Yes. Enter peak torque in Nm and select the metric option. The calculator converts values internally and still reports both units in the results.
Use CSV for spreadsheets, comparisons, and data archiving. Use PDF when you need a clean report for tuning notes, project reviews, or client sharing.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.