Crawl Ratio Calculator
Calculate your total crawl ratio from transmission 1st gear, transfer case low range, and axle ratio. 60:1 is a minimum, 100:1+ is ideal for serious rock crawling.
Transmission — 1st Gear Ratio
Transfer Case — Low Range Ratio
Jeep TJ/JK 1997–2018
Axle Ratio
:1
Total Crawl Ratio
42.7:1
Adequate
OK for mild trails; limited for serious rock work
Trans 1st
3.83:1
TC Low
2.720:1
Axle
4.10:1
Crawl Ratio Quality Scale
Under 40:1InsufficientTrails only; limited in any serious obstacle
40:1–60:1AdequateOK for mild 4x4 use and moderate trails
60:1–80:1GoodSolid all-around; handles most trails comfortably
80:1–100:1Very GoodStrong capability; serious trail and rock use
100:1–150:1ExcellentRock crawler territory; fine throttle control
150:1+ExtremeCompetition/dedicated rock crawler
Formula: Crawl Ratio = 1st gear × TC low range × axle ratio. Higher crawl ratio = more torque multiplication at the wheels = better low-speed control on rocks. Most factory rigs run 40:1–50:1; rock crawlers aim for 100:1+.