Unless you are doing speed estimation,
you only need to input your tire size.

# of cells:
average voltage:
tire width:
KV rating:
lowest spur:
lowest pinion:


total voltage: 15.68
RPM: 42822.08

Emaxx Speed Estimator

Note: This is just an attempt at estimating top speed.
For my Feigao 9L (this page's default KV rating) it's almost perfect.
For the HV's 4400 KV rating, it isn't even close. Probably because it doesn't come close to 4400 RPM per volt under load.

Calculation:
PI = 3.14
first gear multiplier = 7.885
second gear multiplier = 4.895
inches in a mile = 63360
tire circumference = tire width * PI
RPM = KV rating x #cells x cell voltage
M.P.H. = RPM x 60 / spur / pinion * internal gear multiplier * tire circumfrence / inches in a mile

1st gear estimated m.p.h.

spur/pinion 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
60 15.5 17 18.6 20.1 21.7 23.2 24.8 26.3 27.9 29.4 31 32.5 34.1 35.6 37.2 38.7 40.3
61 15.2 16.8 18.3 19.8 21.3 22.8 24.4 25.9 27.4 28.9 30.5 32 33.5 35 36.6 38.1 39.6
62 15 16.5 18 19.5 21 22.5 24 25.5 27 28.5 30 31.5 33 34.5 36 37.5 39
63 14.7 16.2 17.7 19.2 20.6 22.1 23.6 25.1 26.5 28 29.5 31 32.4 33.9 35.4 36.9 38.3
64 14.5 16 17.4 18.9 20.3 21.8 23.2 24.7 26.1 27.6 29 30.5 31.9 33.4 34.8 36.3 37.7
65 14.3 15.7 17.2 18.6 20 21.4 22.9 24.3 25.7 27.2 28.6 30 31.4 32.9 34.3 35.7 37.2
66 14.1 15.5 16.9 18.3 19.7 21.1 22.5 23.9 25.3 26.7 28.2 29.6 31 32.4 33.8 35.2 36.6
67 13.9 15.3 16.6 18 19.4 20.8 22.2 23.6 25 26.3 27.7 29.1 30.5 31.9 33.3 34.7 36.1
68 13.7 15 16.4 17.8 19.1 20.5 21.9 23.2 24.6 26 27.3 28.7 30.1 31.4 32.8 34.2 35.5
69 13.5 14.8 16.2 17.5 18.8 20.2 21.5 22.9 24.2 25.6 26.9 28.3 29.6 31 32.3 33.7 35
70 13.3 14.6 15.9 17.3 18.6 19.9 21.2 22.6 23.9 25.2 26.5 27.9 29.2 30.5 31.9 33.2 34.5
71 13.1 14.4 15.7 17 18.3 19.6 20.9 22.2 23.6 24.9 26.2 27.5 28.8 30.1 31.4 32.7 34
72 12.9 14.2 15.5 16.8 18.1 19.4 20.6 21.9 23.2 24.5 25.8 27.1 28.4 29.7 31 32.3 33.5
73 12.7 14 15.3 16.5 17.8 19.1 20.4 21.6 22.9 24.2 25.5 26.7 28 29.3 30.5 31.8 33.1
74 12.6 13.8 15.1 16.3 17.6 18.8 20.1 21.3 22.6 23.9 25.1 26.4 27.6 28.9 30.1 31.4 32.6

2nd gear estimated m.p.h.

spur/pinion 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
60 24.9 27.4 29.9 32.4 34.9 37.4 39.9 42.4 44.9 47.4 49.9 52.4 54.9 57.4 59.9 62.4 64.8
61 24.5 27 29.4 31.9 34.3 36.8 39.3 41.7 44.2 46.6 49.1 51.5 54 56.4 58.9 61.3 63.8
62 24.1 26.6 29 31.4 33.8 36.2 38.6 41 43.4 45.9 48.3 50.7 53.1 55.5 57.9 60.3 62.8
63 23.8 26.1 28.5 30.9 33.3 35.6 38 40.4 42.8 45.1 47.5 49.9 52.3 54.6 57 59.4 61.8
64 23.4 25.7 28.1 30.4 32.7 35.1 37.4 39.8 42.1 44.4 46.8 49.1 51.4 53.8 56.1 58.5 60.8
65 23 25.3 27.6 29.9 32.2 34.5 36.8 39.1 41.4 43.7 46 48.3 50.6 53 55.3 57.6 59.9
66 22.7 24.9 27.2 29.5 31.7 34 36.3 38.5 40.8 43.1 45.3 47.6 49.9 52.1 54.4 56.7 59
67 22.3 24.6 26.8 29 31.3 33.5 35.7 38 40.2 42.4 44.7 46.9 49.1 51.4 53.6 55.8 58.1
68 22 24.2 26.4 28.6 30.8 33 35.2 37.4 39.6 41.8 44 46.2 48.4 50.6 52.8 55 57.2
69 21.7 23.9 26 28.2 30.4 32.5 34.7 36.9 39 41.2 43.4 45.5 47.7 49.9 52.1 54.2 56.4
70 21.4 23.5 25.7 27.8 29.9 32.1 34.2 36.3 38.5 40.6 42.8 44.9 47 49.2 51.3 53.4 55.6
71 21.1 23.2 25.3 27.4 29.5 31.6 33.7 35.8 37.9 40 42.2 44.3 46.4 48.5 50.6 52.7 54.8
72 20.8 22.9 24.9 27 29.1 31.2 33.3 35.3 37.4 39.5 41.6 43.6 45.7 47.8 49.9 52 54
73 20.5 22.5 24.6 26.6 28.7 30.7 32.8 34.8 36.9 38.9 41 43 45.1 47.1 49.2 51.2 53.3
74 20.2 22.2 24.3 26.3 28.3 30.3 32.4 34.4 36.4 38.4 40.4 42.5 44.5 46.5 48.5 50.6 52.6

Emaxx Final gear ratios

This is the final gear ratio with the stock diffs.

calculation:
first gear multiplier = 7.885
second gear multiplier = 4.895
FGR = spur / pinion x internal gear multiplier

1st gear final gear ratios

spur/pinion 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
60 47.3 43 39.4 36.4 33.8 31.5 29.6 27.8 26.3 24.9 23.7 22.5 21.5 20.6 19.7 18.9 18.2
61 48.1 43.7 40.1 37 34.4 32.1 30.1 28.3 26.7 25.3 24 22.9 21.9 20.9 20 19.2 18.5
62 48.9 44.4 40.7 37.6 34.9 32.6 30.6 28.8 27.2 25.7 24.4 23.3 22.2 21.3 20.4 19.6 18.8
63 49.7 45.2 41.4 38.2 35.5 33.1 31 29.2 27.6 26.1 24.8 23.7 22.6 21.6 20.7 19.9 19.1
64 50.5 45.9 42.1 38.8 36 33.6 31.5 29.7 28 26.6 25.2 24 22.9 21.9 21 20.2 19.4
65 51.3 46.6 42.7 39.4 36.6 34.2 32 30.1 28.5 27 25.6 24.4 23.3 22.3 21.4 20.5 19.7
66 52 47.3 43.4 40 37.2 34.7 32.5 30.6 28.9 27.4 26 24.8 23.7 22.6 21.7 20.8 20
67 52.8 48 44 40.6 37.7 35.2 33 31.1 29.3 27.8 26.4 25.2 24 23 22 21.1 20.3
68 53.6 48.7 44.7 41.2 38.3 35.7 33.5 31.5 29.8 28.2 26.8 25.5 24.4 23.3 22.3 21.4 20.6
69 54.4 49.5 45.3 41.9 38.9 36.3 34 32 30.2 28.6 27.2 25.9 24.7 23.7 22.7 21.8 20.9
70 55.2 50.2 46 42.5 39.4 36.8 34.5 32.5 30.7 29 27.6 26.3 25.1 24 23 22.1 21.2
71 56 50.9 46.7 43.1 40 37.3 35 32.9 31.1 29.5 28 26.7 25.4 24.3 23.3 22.4 21.5
72 56.8 51.6 47.3 43.7 40.6 37.8 35.5 33.4 31.5 29.9 28.4 27 25.8 24.7 23.7 22.7 21.8
73 57.6 52.3 48 44.3 41.1 38.4 36 33.9 32 30.3 28.8 27.4 26.2 25 24 23 22.1
74 58.3 53 48.6 44.9 41.7 38.9 36.5 34.3 32.4 30.7 29.2 27.8 26.5 25.4 24.3 23.3 22.4

2nd gear final gear ratios

spur/pinion 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
60 29.4 26.7 24.5 22.6 21 19.6 18.4 17.3 16.3 15.5 14.7 14 13.3 12.8 12.2 11.7 11.3
61 29.9 27.1 24.9 23 21.3 19.9 18.7 17.6 16.6 15.7 14.9 14.2 13.6 13 12.4 11.9 11.5
62 30.3 27.6 25.3 23.3 21.7 20.2 19 17.9 16.9 16 15.2 14.5 13.8 13.2 12.6 12.1 11.7
63 30.8 28 25.7 23.7 22 20.6 19.3 18.1 17.1 16.2 15.4 14.7 14 13.4 12.8 12.3 11.9
64 31.3 28.5 26.1 24.1 22.4 20.9 19.6 18.4 17.4 16.5 15.7 14.9 14.2 13.6 13.1 12.5 12
65 31.8 28.9 26.5 24.5 22.7 21.2 19.9 18.7 17.7 16.7 15.9 15.2 14.5 13.8 13.3 12.7 12.2
66 32.3 29.4 26.9 24.9 23.1 21.5 20.2 19 17.9 17 16.2 15.4 14.7 14 13.5 12.9 12.4
67 32.8 29.8 27.3 25.2 23.4 21.9 20.5 19.3 18.2 17.3 16.4 15.6 14.9 14.3 13.7 13.1 12.6
68 33.3 30.3 27.7 25.6 23.8 22.2 20.8 19.6 18.5 17.5 16.6 15.9 15.1 14.5 13.9 13.3 12.8
69 33.8 30.7 28.1 26 24.1 22.5 21.1 19.9 18.8 17.8 16.9 16.1 15.4 14.7 14.1 13.5 13
70 34.3 31.1 28.6 26.4 24.5 22.8 21.4 20.2 19 18 17.1 16.3 15.6 14.9 14.3 13.7 13.2
71 34.8 31.6 29 26.7 24.8 23.2 21.7 20.4 19.3 18.3 17.4 16.5 15.8 15.1 14.5 13.9 13.4
72 35.2 32 29.4 27.1 25.2 23.5 22 20.7 19.6 18.5 17.6 16.8 16 15.3 14.7 14.1 13.6
73 35.7 32.5 29.8 27.5 25.5 23.8 22.3 21 19.9 18.8 17.9 17 16.2 15.5 14.9 14.3 13.7
74 36.2 32.9 30.2 27.9 25.9 24.1 22.6 21.3 20.1 19.1 18.1 17.2 16.5 15.7 15.1 14.5 13.9

Emaxx Rollout

This is the rollout with stock diffs. If you put bigger/smaller tires on your truck, use this table to try to keep the same rollout.
This will give you similiar performance, and help make sure you are not over geared.

Calculation:
PI = 3.14
Rollout = tire width x PI / spur / pinion

1st gear rollout

spur/pinion 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
60 0.38 0.42 0.46 0.5 0.53 0.57 0.61 0.65 0.69 0.73 0.76 0.8 0.84 0.88 0.92 0.95 0.99
61 0.38 0.41 0.45 0.49 0.53 0.56 0.6 0.64 0.68 0.71 0.75 0.79 0.83 0.86 0.9 0.94 0.98
62 0.37 0.41 0.44 0.48 0.52 0.55 0.59 0.63 0.67 0.7 0.74 0.78 0.81 0.85 0.89 0.92 0.96
63 0.36 0.4 0.44 0.47 0.51 0.55 0.58 0.62 0.65 0.69 0.73 0.76 0.8 0.84 0.87 0.91 0.95
64 0.36 0.39 0.43 0.47 0.5 0.54 0.57 0.61 0.64 0.68 0.72 0.75 0.79 0.82 0.86 0.89 0.93
65 0.35 0.39 0.42 0.46 0.49 0.53 0.56 0.6 0.63 0.67 0.7 0.74 0.78 0.81 0.85 0.88 0.92
66 0.35 0.38 0.42 0.45 0.49 0.52 0.56 0.59 0.62 0.66 0.69 0.73 0.76 0.8 0.83 0.87 0.9
67 0.34 0.38 0.41 0.44 0.48 0.51 0.55 0.58 0.62 0.65 0.68 0.72 0.75 0.79 0.82 0.85 0.89
68 0.34 0.37 0.4 0.44 0.47 0.51 0.54 0.57 0.61 0.64 0.67 0.71 0.74 0.77 0.81 0.84 0.88
69 0.33 0.37 0.4 0.43 0.46 0.5 0.53 0.56 0.6 0.63 0.66 0.7 0.73 0.76 0.8 0.83 0.86
70 0.33 0.36 0.39 0.43 0.46 0.49 0.52 0.56 0.59 0.62 0.65 0.69 0.72 0.75 0.79 0.82 0.85
71 0.32 0.35 0.39 0.42 0.45 0.48 0.52 0.55 0.58 0.61 0.65 0.68 0.71 0.74 0.77 0.81 0.84
72 0.32 0.35 0.38 0.41 0.45 0.48 0.51 0.54 0.57 0.6 0.64 0.67 0.7 0.73 0.76 0.8 0.83
73 0.31 0.35 0.38 0.41 0.44 0.47 0.5 0.53 0.56 0.6 0.63 0.66 0.69 0.72 0.75 0.78 0.82
74 0.31 0.34 0.37 0.4 0.43 0.46 0.5 0.53 0.56 0.59 0.62 0.65 0.68 0.71 0.74 0.77 0.8

2nd gear rollout

spur/pinion 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
60 0.62 0.68 0.74 0.8 0.86 0.92 0.98 1.05 1.11 1.17 1.23 1.29 1.35 1.41 1.48 1.54 1.6
61 0.6 0.67 0.73 0.79 0.85 0.91 0.97 1.03 1.09 1.15 1.21 1.27 1.33 1.39 1.45 1.51 1.57
62 0.6 0.65 0.71 0.77 0.83 0.89 0.95 1.01 1.07 1.13 1.19 1.25 1.31 1.37 1.43 1.49 1.55
63 0.59 0.64 0.7 0.76 0.82 0.88 0.94 1 1.05 1.11 1.17 1.23 1.29 1.35 1.41 1.46 1.52
64 0.58 0.63 0.69 0.75 0.81 0.86 0.92 0.98 1.04 1.1 1.15 1.21 1.27 1.33 1.38 1.44 1.5
65 0.57 0.62 0.68 0.74 0.79 0.85 0.91 0.97 1.02 1.08 1.14 1.19 1.25 1.31 1.36 1.42 1.48
66 0.56 0.62 0.67 0.73 0.78 0.84 0.89 0.95 1.01 1.06 1.12 1.17 1.23 1.29 1.34 1.4 1.45
67 0.55 0.61 0.66 0.72 0.77 0.83 0.88 0.94 0.99 1.05 1.1 1.16 1.21 1.27 1.32 1.38 1.43
68 0.54 0.6 0.65 0.71 0.76 0.81 0.87 0.92 0.98 1.03 1.09 1.14 1.19 1.25 1.3 1.36 1.41
69 0.53 0.59 0.64 0.7 0.75 0.8 0.86 0.91 0.96 1.02 1.07 1.12 1.18 1.23 1.28 1.34 1.39
70 0.53 0.58 0.63 0.69 0.74 0.79 0.84 0.9 0.95 1 1.05 1.11 1.16 1.21 1.27 1.32 1.37
71 0.52 0.57 0.62 0.68 0.73 0.78 0.83 0.88 0.94 0.99 1.04 1.09 1.14 1.2 1.25 1.3 1.35
72 0.51 0.56 0.62 0.67 0.72 0.77 0.82 0.87 0.92 0.97 1.03 1.08 1.13 1.18 1.23 1.28 1.33
73 0.51 0.56 0.61 0.66 0.71 0.76 0.81 0.86 0.91 0.96 1.01 1.06 1.11 1.16 1.21 1.26 1.31
74 0.5 0.55 0.6 0.65 0.7 0.75 0.8 0.85 0.9 0.95 1 1.05 1.1 1.15 1.2 1.25 1.3