Automotive Calculators

ArrayKit's automotive calculators help you work out the running costs and performance figures of a vehicle — the fuel cost of a trip, gas mileage in MPG or L/100km, engine horsepower from quarter-mile or trap-speed data, and tire size dimensions and comparisons. Each calculator runs entirely in your browser, so the figures you enter stay on your device and nothing is uploaded. Use them to budget a road trip, compare the efficiency of two cars, check a tire upgrade or estimate power — with standard formulas and instant results.

• Fuel Cost Calculator — Estimate the fuel cost of a trip from distance, efficiency and price.
• Gas Mileage Calculator — Calculate MPG or L/100km from distance and fuel used, and convert.
• Mileage Reimbursement Calculator — Calculate mileage reimbursement from miles driven and a per-mile rate.
• Horsepower Calculator — Calculate horsepower from torque and RPM, or convert power units.
• Engine Horsepower Calculator — Estimate engine horsepower from quarter-mile ET or trap speed.
• Tire Size Calculator — Decode a tire size and compare two sizes for diameter and speedo error.
• VIN Decoder — Decode a 17-character VIN into maker, country, model year and plant, and verify its check digit.
• Fuel Economy Converter — Convert between MPG (US), MPG (UK), L/100km and km/L, with trip fuel and cost.
• Gear Ratio Calculator — Work out speed at RPM, RPM at speed and gear ratios from tooth counts and tyre size.
• Engine Displacement Calculator — Calculate engine displacement in cc, litres and cubic inches from bore, stroke and cylinders.
• Braking Distance Calculator — Stopping distance from speed, reaction time and road surface — thinking plus braking.
• EV Charging Cost Calculator — What a charge costs from battery size, charge window and electricity price, vs petrol.
• Tire Pressure Converter — Convert tyre pressure between psi, bar, kPa and kgf/cm², and correct for temperature.
• Wheel Offset Calculator — Convert wheel offset to backspacing and compare how two wheels sit on the hub.
• Compression Ratio Calculator — Work out static, dynamic and boosted compression ratio from your engine measurements.
• OBD2 Code Lookup — Decode any check-engine trouble code into system, subsystem and likely causes.
• Tire Load Index & Speed Rating — Read the numbers after a tire size as a weight limit and a top speed.
• Towing Capacity Calculator — Work out how much you can really tow from GCWR, GVWR, payload and tongue weight.

Frequently asked questions

Do I need to install anything to use these automotive calculators?

No. Every automotive calculator on ArrayKit runs directly in your browser, so there is nothing to install and the figures you enter are processed locally on your device.

Do the automotive calculators work with both MPG and L/100km?

Yes. The fuel and mileage calculators support US MPG, UK MPG and litres per 100 km, with unit toggles so you can work in whichever your car and country use.

Do the automotive calculators upload my data?

No. All of the math happens in your browser, so the numbers you type never leave your device or get uploaded to ArrayKit.

Which automotive calculators does ArrayKit offer?

The category covers fuel cost, gas mileage and trip mileage, engine and drivetrain horsepower estimates, and tire size dimensions and comparison calculators.