Off-Road Calculators: Free Tools for Tires, Gears, Winches and Trails
Free off-road calculators for real trail decisions: what bigger tires do to your speedometer and gearing, how far to air down, what winch you need, and whether a crossing or ledge is safe to try. Each tool runs right in your browser, shows the math it uses, and links to the guide behind it.
Tires & wheels
Tire size calculator
Compare your stock and new tires: diameter, real speed vs your speedometer, clearance gained and effective gearing.
Open the tire size calculator
Air-down tire pressure calculator
Starting trail PSI for sand, rocks, mud, snow and trails, on standard or beadlock wheels.
Open the air-down tire pressure calculator
Wheel offset and backspacing calculator
Turn wheel width and offset into backspacing, with stock vs recommended specs for 35s on Wrangler and Tacoma.
Open the wheel offset and backspacing calculatorGearing & drivetrain
Regear calculator
The axle ratio that restores your gearing after bigger tires, the closest common ratio and your highway RPM.
Open the regear calculator
Bronco crawl ratio calculator
Crawl ratio and low-range speed for Bronco transmission, transfer case and axle combinations.
Open the bronco crawl ratio calculatorRecovery
Winch size calculator
Size a winch with WARN's 1.5x GVWR rule and see how pull drops on each layer of rope.
Open the winch size calculatorTrail & terrain
Approach angle calculator
Approach, departure and breakover angles, and what bigger tires or a lift really change.
Open the approach angle calculator
Water crossing depth checker
A go/no-go check for a water crossing, using your fording rating, current and bottom conditions.
Open the water crossing depth checkerHow to use these calculators
Start with the numbers printed on your vehicle: the tire size on the sidewall, the road pressure and GVWR on the driver’s door placard, and your axle ratio (often on the window sticker, the axle tag or the build sheet). Results are estimates based on published specs and standard formulas, so treat them as a starting point and check your owner’s manual or a qualified shop before you buy parts.
Planning bigger tires? Run the tire size calculator first, then the regear calculator and the offset and backspacing calculator. Heading out this weekend? Grab the free recovery and water-crossing checklist.
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