Speed Estimator
Estimate theoretical top speed from motor, gearing, and tire size.
41.7mph (theoretical)
Final Drive Ratio
8.16:1
Wheel RPM
3,990
⚠ Theoretical estimate only. Real-world speed varies with terrain, sag voltage, temperature, and mechanical losses.
Matching motors in this KV range
Common battery voltages
2S LiPo = 7.4V · 3S = 11.1V · 4S = 14.8V · 6S = 22.2V · 8S = 29.6V · 12S = 44.4V
Measuring tire diameter
Inflate tires to normal running pressure, then measure the outer diameter with calipers or a ruler. Use millimeters for this calculator.
Why is my actual speed lower?
This estimates no-load motor RPM at full voltage. In practice, voltage sags under load, terrain adds resistance, and mechanical losses reduce output. The drivetrain efficiency field accounts for some of this — 0.80–0.85 is realistic for most vehicles.