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 rpm mph 4500 rpm mph
1500 rpm mph 5000 rpm mph
2000 rpm mph 5500 rpm mph
2500 rpm mph 6000 rpm mph
3000 rpm mph 6500 rpm mph
3500 rpm mph 7000 rpm mph
4000 rpm mph 7500 rpm mph

 

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
5 7.80 6.8 10.61 8.55 13.34 10.3 16.07
5.05 7.88 6.85 10.69 8.6 13.42 10.35 16.15
5.1 7.96 6.9 10.76 8.65 13.49 10.4 16.22
5.15 8.03 6.95 10.84 8.7 13.57 10.45 16.30
5.2 8.11 7 10.92 8.75 13.65 10.5 16.38
5.25 8.19 7.05 11.00 8.8 13.73 10.55 16.46
5.3 8.27 7.1 11.08 8.85 13.81 10.6 16.54
5.35 8.35 7.15 11.15 8.9 13.88 10.65 16.61
5.4 8.42 7.2 11.23 8.95 13.96 10.7 16.69
5.45 8.50 7.25 11.31 9 14.04 10.75 16.77
5.5 8.58 7.3 11.39 9.05 14.12 10.8 16.85
5.55 8.66 7.35 11.47 9.1 14.20 10.85 16.93
5.6 8.74 7.4 11.54 9.15 14.27 10.9 17.00
5.65 8.81 7.45 11.62 9.2 14.35 10.95 17.08
5.7 8.89 7.5 11.70 9.25 14.43 11 17.16
5.75 8.97 7.55 11.78 9.3 14.51 11.05 17.24
5.8 9.05 7.6 11.86 9.35 14.59 11.1 17.32
5.85 9.13 7.65 11.93 9.4 14.66 11.15 17.39
5.9 9.20 7.7 12.01 9.45 14.74 11.2 17.47
5.95 9.28 7.75 12.09 9.5 14.82 11.25 17.55
6 9.36 7.8 12.17 9.55 14.90 11.3 17.63
6.05 9.44 7.85 12.25 9.6 14.98 11.35 17.71
6.1 9.52 7.9 12.32 9.65 15.05 11.4 17.78
6.15 9.59 7.95 12.40 9.7 15.13 11.45 17.86
6.2 9.67 8 12.48 9.75 15.21 11.5 17.94
6.25 9.75 8.05 12.56 9.8 15.29 11.55 18.02
6.3 9.83 8.1 12.64 9.85 15.37 11.6 18.10
6.35 9.91 8.15 12.71 9.9 15.44 11.65 18.17
6.4 9.98 8.2 12.79 9.95 15.52 11.7 18.25
6.45 10.06 8.25 12.87 10 15.60 11.75 18.33
6.5 10.14 8.3 12.95 10.05 15.68 11.8 18.41
6.55 10.22 8.35 13.03 10.1 15.76 11.85 18.49
6.6 10.30 8.4 13.10 10.15 15.83 11.9 18.56
6.65 10.37 8.45 13.18 10.2 15.91 11.95 18.64
6.7 10.45 8.5 13.26 10.25 15.99 12 18.72
6.75 10.53