Gear Calculators enter 5 of the 6 in green press CALC
Tire Diameter: :1   Transmission Ratio: :1
Diff Ratio: :1   TransferCase Ratio: :1
RPM: :1   MPH: :1
  Crawl  
  
  Ratio 


GEAR RATIO, TIRE SIZE, CRAWL RATIO, ETC. CALCULATORS

This calc can be used to find any (one) missing value.
Solve for your MPH.
Solve for your RPM.
Solve for your Differential Ratio.
Solve for your Tire Diameter.
Solve for your Transmission Ratio.
Solve for your Transfer Case Ratio.
Solve for your Crawl Ratio.

If your tires are bigger than stock you probably, like myself, have spend a lot of time trying to WAG (wild ass guess) your actual MPH when going down the road. If you know your gear ratio and tire size you can get a fairly close idea here. Fill in all entries except the one you want an answer to (in green section).

If you'd like to find your overall crawl ratio, enter the Diff/Trans/TransfCase ratios. Remember, the yellow section (crawl ratio) is only for output only, do not type anything in this box.

Clicking on the Transmission or TransferCase links will jump to bottom of this page.



Formulas used


and

These calculators are color coded by function
All fields Required Leave ONE field blank Supply ONLY one field Results Only



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Popular Transmission Ratios
Manual
Transmissions:

AMC SR4 (Borg-Warner)
Jeep
1st 2nd 3rd 4th
4.07 2.39 1.49 1.00
SM 420
1st 2nd 3rd 4th
7.00 3.60 1.70 1.00
SM 465 (MUNCIE)
GM, Chevy
1st 2nd 3rd 4th
6.55 3.58 1.57 1.00
T-176
Jeep
1st 2nd 3rd 4th
3.52 2.27 1.46 1.00
T-177
Jeep
1st 2nd 3rd 4th
3.82 2.29 1.46 1.00
T-178
Jeep
1st 2nd 3rd 4th
3.00 2.08 1.46 1.00
Mazda 5-spd
Ford, Mazda?
1st 2nd 3rd 4th 5th
3.40 2.20 1.50 1.00 0.79
NV3500
Chevy
1st 2nd 3rd 4th 5th
4.02 2.32 1.40 1.00 0.73
NV4500
Chevy
1st 2nd 3rd 4th 5th
5.61 3.04 1.67 1.00 0.73
ZF S6-650
Chevy
1st 2nd 3rd 4th 5th 6th
5.79 3.31 2.10 1.31 1.00 0.76
Automatic
Transmissions:

TH 350
Chevy
1st 2nd 3rd
2.52 1.52 1.00
TH 400
GM, Chevy, Jeep
1st 2nd 3rd
2.48 1.48 1.00
TH 700R4
GM, Chevy
1st 2nd 3rd 4th
3.06 1.62 1.00 0.70
4L80-E
Chevy
1st 2nd 3rd 4th
3.10 1.48 1.00 0.75
Allison 1000 Series
Chevy
1st 2nd 3rd 4th 5th
3.10 1.81 1.41 1.00 0.71
C-4/C-5/C-6
Ford
1st 2nd 3rd
2.46 1.46 1.00
Ford AOD
Ford
1st 2nd 3rd 4th
2.40 1.47 1.00 0.67
TORQUEFLITE 727
Jeep, Dodge
1st 2nd 3rd
2.45 1.45 1.00
       Popular Transfer Case Ratios
 
 

Dana 300
Jeep
Lo Hi
2.62 1.00
Borg Warner 1356
Ford
Lo Hi
2.69 1.00
DANA/Spicer 18
Jeep
Lo Hi
2.46 1.00
DANA/Spicer 20
Jeep, IH (TC-145), GM, Ford
Lo Hi
2.00 1.00
NP 203
Chevy, Ford, Dodge
Lo Hi
2.00 1.00
NP 205
Chevy, Ford, Dodge, IH
Lo Hi
1.98 1.00
NP 207/208
Jeep, Chevy, Ford, Dodge
Lo Hi
2.61 1.00
NP 231
Jeep (YJ)
Lo Hi
2.72 1.00
Toyota (67-74)
Land Cruiser
Lo Hi
2.31 1.00