Multiply first gear, transfer-case low, and axle ratio for off-road crawl ratio, then see street / moderate / serious / extreme — free, private, no signup.
49.74
Crawl ratio
49.7 : 1
Display
Moderate off-road
Category
Rough guide: under 40:1 street/light trail · 40–60:1 moderate · 60–100:1 serious crawling · over 100:1 extreme.
Does not include portal hubs, aftermarket reductions, or tire scrub — real crawl feel also depends on tire diameter and terrain.
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Crawl ratio is the overall reduction in low range: transmission first × transfer-case low × differential (axle) ratio. Example: 4.0 first × 2.72 t-case × 4.10 axle ≈ 44.5 : 1. That number tells you how slowly the tires turn for a given engine speed on the rocks — not highway RPM, and not tire diameter.
The workspace labels the result: under 40 street-ish, 40–60 moderate trail, 60–100 serious, over 100 extreme. Those bins are common shop talk, not a sanctioning-body rule. A stock 4x4 with 3.42 gears often sits in the street/moderate end until you add a deeper t-case or axle.
First 1–6, t-case low 1–5, axle 1–10 cover typical manuals, dual-range boxes, and light-truck gears. Portal boxes, extra reductions, and a 40-inch tire’s extra leverage are not multiplied in. If you only need axle ratio from tooth counts, use Gear Ratio Calculator first, then paste it here.
No VIN and no upload. The three ratios stay in the tab. Close the page and they are gone. This will not tell you if a locker is engaged or whether the tires will claw — it is reduction math for planning a re-gear.
From the transmission spec (for example 4.01 or 3.32). Use crawler first, not sixth.
Stock boxes are often ~2.0–2.7; aftermarket crawler boxes can be 4:1 or more. Use 1.0 only if you have no reduction case.
3.73, 4.10, 5.13, and similar. Count teeth with Gear Ratio Calculator if the cover is off.
Product of the three, two decimals, plus street / moderate / serious / extreme. Recalculate after a t-case or axle swap.
Straight answers on privacy, limits, and how the workspace behaves.
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