overlanding.tools is a set of free calculators for overland builders. We built them because the math is real. Gear ratios. Winch physics. Electrical sizing. We wanted them in one place, fast, with no login.
What you’ll find here
Fifteen free calculators in three buckets. Vehicle and drivetrain math handles regear, lift safety, and weight. Trail and recovery covers airing down, winch pull, rope sizing, angles, and fuel range. Camp and systems sizes battery banks, water needs, cook times, and rack loads.
Every input takes Imperial or metric units. Every result shows a number plus a verdict in plain words. Every page has an explainer covering the formula and what it assumes. You can sanity-check the math, adapt it for your build, or embed any tool on your own site with ?embed=1.
Our Methodology
Each calculator uses documented formulas and published data sources. Where we make a judgment call — like the PSI drop for airing down on sand — we cite where the call comes from. Sources include SAE J689 for vehicle angles, U.S. Army FM 20-22 for ground resistance, TRA (Tire and Rim Association) charts for tire load ranges, and field guides from Overland Expo and Jonathan Hanson.
Affiliate Disclosure
overlanding.tools earns a commission on qualifying purchases through affiliate links. This does not change our calculator results or what we recommend. We link to gear because it fits the calculation — not the other way around.
How we maintain this site
We add new calculators when we find a gap in build planning that math can fill. We fix bugs when users report them. We keep formulas current as standards change. Every change is logged in our public Git history on GitHub.
We do not collect emails. We do not run pop-ups or interstitials. Page load stays fast on slow trail Wi-Fi. The site works on a phone. It works without JavaScript for read-only pages. The calculators need JavaScript to run the math.
Contact
Questions, corrections, or feedback: contact@overlanding.tools