Calculate HP from Speed

Vehicle weight in pounds(with driver)
 lbs

Trap speed at end of 1/4 mi.
 m.p.h.


Uncorrected HP is :

 

 

 

Calculate HP from ET

Vehicle weight in pounds(with driver)
 lbs

ET in seconds
 sec


Uncorrected HP is :

 



Calculate MPH for RPM
Tire diameter
 		Gear Ratio

This calculation is for a final drive ratio of 1:1
1000 rpmmph4500 rpmmph
1500 rpmmph5000 rpmmph
2000 rpmmph5500 rpmmph
2500 rpmmph6000 rpmmph
3000 rpmmph6500 rpmmph
3500 rpmmph7000 rpmmph
4000 rpmmph7500 rpmmph

 

  


Calculate Rear End Gear Ratio
Enter the tire diameter in inches, the rpm’s of the engine at entered speed as indicated by your speedometer in mph. This calculator is for a 1:1 final drive ratio.
Tire Diameter (in)
 		RPM
 		Speed at RPM (mph)


Final Rear Gear Ratio

 

1/8-MILE TO 1/4-MILE CONVERSION TABLE

1/8-mile ET

1/4-mile ET

1/8-mile ET

1/4-mile ET

1/8-mile ET

1/4-mile ET

1/8-mile ET

1/4-mile ET

57.806.8 10.61 8.55 13.34 10.3 16.07
5.057.886.85 10.69 8.6 13.42 10.35 16.15
5.17.966.9 10.76 8.65 13.49 10.4 16.22
5.158.036.95 10.84 8.7 13.57 10.45 16.30
5.28.117 10.92 8.75 13.65 10.5 16.38
5.258.197.05 11.00 8.8 13.73 10.55 16.46
5.38.277.1 11.08 8.85 13.81 10.6 16.54
5.358.357.15 11.15 8.9 13.88 10.65 16.61
5.48.427.2 11.23 8.95 13.96 10.7 16.69
5.458.507.25 11.31 9 14.04 10.75 16.77
5.58.587.3 11.39 9.05 14.12 10.8 16.85
5.558.667.35 11.47 9.1 14.20 10.85 16.93
5.68.747.4 11.54 9.15 14.27 10.9 17.00
5.658.817.45 11.62 9.2 14.35 10.95 17.08
5.78.897.5 11.70 9.25 14.43 11 17.16
5.758.977.55 11.78 9.3 14.51 11.05 17.24
5.89.057.6 11.86 9.35 14.59 11.1 17.32
5.859.137.65 11.93 9.4 14.66 11.15 17.39
5.99.207.7 12.01 9.45 14.74 11.2 17.47
5.959.287.75 12.09 9.5 14.82 11.25 17.55
69.367.8 12.17 9.55 14.90 11.3 17.63
6.059.447.85 12.25 9.6 14.98 11.35 17.71
6.19.527.9 12.32 9.65 15.05 11.4 17.78
6.159.597.95 12.40 9.7 15.13 11.45 17.86
6.29.678 12.48 9.75 15.21 11.5 17.94
6.259.758.05 12.56 9.8 15.29 11.55 18.02
6.39.838.1 12.64 9.85 15.37 11.6 18.10
6.359.918.15 12.71 9.9 15.44 11.65 18.17
6.49.988.2 12.79 9.95 15.52 11.7 18.25
6.4510.068.25 12.87 10 15.60 11.75 18.33
6.510.148.3 12.95 10.05 15.68 11.8 18.41
6.5510.228.35 13.03 10.1 15.76 11.85 18.49
6.610.308.4 13.10 10.15 15.83 11.9 18.56
6.6510.378.45 13.18 10.2 15.91 11.95 18.64
6.710.458.5 13.26 10.25 15.99 12 18.72
6.7510.53