# PitStopCalc

> Free calculators for trucks, tractors and trailers -- fuel and DEF, cost
> per mile, axle loading, cargo and pallets, gear ratios, engine
> displacement, towing and payload, tyre wear, hours of service and shop
> math. Every calculator publishes the formula it uses on the page,
> alongside reference tables, a worked example and the cases where the
> estimate breaks down. No account, no app, nothing uploaded.

Figures are estimates for planning. Manufacturer ratings, plating and the
regulations of your jurisdiction govern; see the disclaimer.

## Calculators

- [Fuel & Fluids Calculator](https://www.pitstopcalc.com/calculators/fuel): Calculate trip fuel cost, diesel exhaust fluid (DEF) consumption, and coolant mix ratio for your vehicle or fleet.
- [Engine Displacement Calculator](https://www.pitstopcalc.com/calculators/engine): Calculate engine displacement in cubic inches (CID), liters, and cc from bore, stroke, and cylinder count.
- [Gear Ratio & Tire Calculator](https://www.pitstopcalc.com/calculators/drivetrain): Calculate engine RPM at a given road speed for your gear ratio and tire size, or speedometer error after a tire size change.
- [Shop Tools](https://www.pitstopcalc.com/calculators/shop): Convert torque units, solve Ohm's Law, and calculate battery amp-hour runtime.
- [Trip Planner](https://www.pitstopcalc.com/calculators/trip): Calculate drive time and arrival, tire pressure change with temperature, and stopping distance by road condition.
- [Hours of Service Calculator](https://www.pitstopcalc.com/calculators/hos): Estimate remaining drive time under the FMCSA 11-hour driving limit and 14-hour on-duty window.
- [Axle Weight Distribution Calculator](https://www.pitstopcalc.com/calculators/axle): Calculate front (steer) and rear (drive) axle weights for a straight truck from curb weight, cargo weight, and load position.
- [Cargo & Load Space Calculator](https://www.pitstopcalc.com/calculators/cargo): Calculate cargo volume and how many pallets fit in a truck bed or trailer based on interior dimensions.
- [Cost Per Mile Calculator](https://www.pitstopcalc.com/calculators/cpm): Calculate your operating cost per mile and a suggested minimum freight rate from fixed and variable trucking costs.
- [Tire Tread Life Calculator](https://www.pitstopcalc.com/calculators/tread): Estimate remaining tire life in miles from tread wear rate and legal minimum tread depth.
- [Towing & Payload Calculator](https://www.pitstopcalc.com/calculators/towing): Calculate remaining payload capacity, maximum towing capacity, and recommended trailer tongue or pin weight.

## Guides

- [DOT Hours-of-Service Compliance Basics](https://www.pitstopcalc.com/guides/hos-compliance): The 11-hour, 14-hour, 30-minute break and 60/70-hour HOS rules under 49 CFR 395, explained — and how to read the calculator's answer.
- [Diesel Engine Maintenance Intervals & Fluids Guide](https://www.pitstopcalc.com/guides/diesel-maintenance-intervals): Typical diesel oil, coolant, DEF and fuel filter service intervals by duty cycle, with a reference table and the standards behind them.
- [How to Read a Loaded-Truck Stopping-Distance Chart](https://www.pitstopcalc.com/guides/stopping-distance): Why a car's stopping-distance formula understates a loaded tractor-trailer's, matched against the FMCSA CDL manual's own 55 mph figures.

## About this site

- [All calculators](https://www.pitstopcalc.com/calculators/)
- [About](https://www.pitstopcalc.com/about): PitStopCalc builds free, accurate calculators for diesel and gasoline engines, tractors, trailers, and wheels.
- [Contact](https://www.pitstopcalc.com/contact): Get in touch with PitStopCalc — questions, bug reports, and calculator requests.
- [Donate](https://www.pitstopcalc.com/donate): Support the development of new free automotive and trucking calculators at PitStopCalc.
- [Privacy Policy](https://www.pitstopcalc.com/privacy-policy): Privacy Policy for PitStopCalc — how we handle cookies, advertising, and data.
- [Terms of Use](https://www.pitstopcalc.com/terms-of-use): Terms of Use for PitStopCalc — the conditions for using these free calculators, and the limits on what their estimates can be relied on for.
- [Disclaimer](https://www.pitstopcalc.com/disclaimer): Disclaimer for PitStopCalc — estimates only, not professional automotive or engineering advice.

## Languages

Every calculator and every page under "About this site" exists in English,
Spanish, French, German, Portuguese and Korean. Locale URLs are prefixed
(/es/, /fr/, /de/, /pt/, /ko/) and declared via hreflang on each page and
in https://www.pitstopcalc.com/sitemap.xml. The guides above are English only.