No sign-up · No paywall · Built for the shop and the road

Free calculators that get the numbers right.

Fuel cost, DEF usage, coolant mix, 2-stroke mix, gear ratios, speedometer error, towing payload, tongue weight, engine displacement, torque conversion, Ohm's Law, battery runtime, trip ETA, tire pressure, stopping distance, hours of service, axle weights, cargo space, cost per mile, tire tread life — enter your numbers, get a straight answer.

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01

Fuel & Fluids

Trip fuel cost, DEF consumption, and coolant mix ratio.

02

Gear Ratio & Tires

Engine RPM at speed, and speedometer error from tire size.

03

Towing & Payload

Payload capacity and trailer tongue weight.

04

Engine Displacement

Bore, stroke, and cylinder count to CID and liters.

05

Shop Tools

Torque conversion, Ohm's Law, and battery runtime.

06

Trip Planner

ETA, tire pressure vs. temperature, and stopping distance.

07

Hours of Service

Remaining drive time under the 11/14-hour rules.

08

Axle Weights

Front/rear axle load distribution for a straight truck.

09

Cargo & Load Space

Cargo volume and pallet count for a bed or trailer.

10

Cost Per Mile

Operating cost per mile and a suggested minimum rate.

11

Tire Tread Life

Remaining tire miles from your current wear rate.

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Built for the shop, the field, and the road

Every calculator here uses standard automotive and trucking-industry formulas — the same math a diesel tech, fleet mechanic, or gearhead would use with a notepad. Enter your numbers and get a straight answer: gallons, ratios, pounds, or cubic inches, plus notes on where the formula comes from so you're not trusting a black box.

Results are estimates for planning purposes. Always confirm critical figures — towing capacity, payload, and gearing — against your vehicle or equipment manufacturer's specs before loading or driving.