Gear Ratio
Tire Diameter

Diff Ratio
:1
RPM

Transmission Ratio
:1
TransferCase Ratio
:1
MPH

Crawl Ratio
Enter any 5 of 6 values (solve for 6th)
Results Only

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 Transfer Case 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.

Formulas used

and

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

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-176Jeep 1st 2nd 3rd 4th 3.52 2.27 1.46 1.00 T-177Jeep 1st 2nd 3rd 4th 3.82 2.29 1.46 1.00 T-178Jeep 1st 2nd 3rd 4th 3.00 2.08 1.46 1.00 Mazda 5-spdFord, Mazda? 1st 2nd 3rd 4th 5th 3.40 2.20 1.50 1.00 0.79 NV3500Chevy 1st 2nd 3rd 4th 5th 4.02 2.32 1.40 1.00 0.73 NV4500Chevy 1st 2nd 3rd 4th 5th 5.61 3.04 1.67 1.00 0.73 ZF S6-650Chevy 1st 2nd 3rd 4th 5th 6th 5.79 3.31 2.10 1.31 1.00 0.76
Automatic
Transmissions:

 TH 350Chevy 1st 2nd 3rd 2.52 1.52 1.00 TH 400GM, Chevy, Jeep 1st 2nd 3rd 2.48 1.48 1.00 TH 700R4GM, Chevy 1st 2nd 3rd 4th 3.06 1.62 1.00 0.70 4L80-EChevy 1st 2nd 3rd 4th 3.10 1.48 1.00 0.75 Allison 1000 SeriesChevy 1st 2nd 3rd 4th 5th 3.10 1.81 1.41 1.00 0.71 C-4/C-5/C-6Ford 1st 2nd 3rd 2.46 1.46 1.00 Ford AODFord 1st 2nd 3rd 4th 2.40 1.47 1.00 0.67 TORQUEFLITE 727Jeep, Dodge 1st 2nd 3rd 2.45 1.45 1.00
Popular Transfer Case Ratios

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