ganak.appAuto Calculators
11 calculators · Updated May 2026
Calculate tire sizes, gear ratios, engine RPM, and towing capacity for your vehicle. Whether you are upgrading wheels, tuning your drivetrain, or checking tow limits, these tools give you precise answers.
Popular in Auto
Tire Size Calculator
Free tire size calculator. Compare two tire sizes side by side for diameter, sidewall, circumference, speedometer error, and ground clearance difference.
Gear Ratio Calculator
Free gear ratio calculator. Find gear ratio from tooth counts, calculate RPM and output speed, vehicle speed, and bicycle gearing with gear inches.
Towing Capacity Calculator
Free towing capacity calculator. Check payload, GCVW, tongue weight, and hitch limits against your vehicle's GVWR and GCWR. Visual safety status bars.
All Auto Calculators
RPM Calculator
Free RPM calculator. Calculate engine RPM from speed, tire size, and gear ratio. Includes pulley RPM, SFM for machining, and torque-to-HP conversion.
Dynamic Compression Calculator
Free dynamic compression ratio calculator. Enter bore, stroke, rod length, cam IVC, and combustion chamber volume to get static and dynamic CR with fuel octane recommendations.
Prop Slip Calculator
Free prop slip calculator. Enter RPM, gear ratio, propeller pitch, and actual boat speed to get slip %, theoretical speed, and a pitch-sizing recommendation. Supports inches/cm and mph/knots/km/h.
2-Stroke Oil Mix Calculator
Calculate the exact amount of 2-stroke oil for any fuel-to-oil ratio. Covers 50:1, 40:1, 32:1 with reference charts for chainsaws, outboards, and more.
E85 Calculator
Free E85 calculator. Find the exact gallons of E85 and gasoline to mix for any target ethanol blend. Accounts for fuel in tank, seasonal E85 variation, and octane.
Quarter Mile Calculator
Calculate quarter-mile elapsed time, trap speed, and required horsepower. Supports Hale, Fox, and Huntington formulas with 1/8-mile conversion and drivetrain corrections.
0-60 Calculator
Free 0-60 mph calculator. Estimate 0-60 time from HP & weight, find required HP, or convert from 1/4-mile ET. Wallace, Hale & Fox formulas with drivetrain.
USADiminished Value Calculator
Free diminished value calculator. Estimate post-accident car value loss using the 17c formula and market-based method. Includes mileage modifier, damage severity adjustment, and step-by-step formula breakdown.
Why Use Auto Calculators?
Getting tire sizes wrong affects your speedometer accuracy, fuel economy, and ride quality. Gear ratio miscalculations can leave your engine over-revving or struggling. These calculators let you compare tire sizes side by side, find the right gear ratios for your setup, and verify your towing capacity before hitching up — all backed by precise formulas used by automotive engineers.