Gear Ratio & Speed Calculator

Gear Ratio & Speed Calculator is the all-in-one transmission calculator, drivetrain simulator, and automotive engineering tool for track racers, off-road builders, and mechanics. Whether you need a precision gear ratio calculator for drag racing, an axle ratio calculator for truck re-gearing, or a crawl ratio simulator for 4x4 rock crawling, this app delivers instant, accurate results. Plan modifications and preview their impact before turning a single wrench. ■ WHAT IF? VEHICLE SETUP SIMULATOR • Compare current setup with a new What If? configuration side by side. • Evaluate changes in tire dimensions, axle & final drive ratios, and transmission swaps. • Compare cruising RPM at 60, 80, 100, 120, and 130 km/h (or mph). • Check top speed and speed at specific RPM intervals (3,000 to redline). • Detailed gear-by-gear ratio and speed delta comparison. • Visual graph comparing current vs new setup curves. • Dedicated impact breakdown cards for tire size, final drive, and transmission swaps. • Experiment freely without modifying your saved Garage profile. ■ RPM & SPEED CALCULATOR • RPM to Speed: Calculate true vehicle speed from engine RPM, gear ratio, final drive axle ratio, and tire dimensions. • Speed to RPM: Find required engine RPM for target cruising and highway speeds to optimize load and fuel economy. ■ GEAR RATIO & FINAL DRIVE (AXLE RATIO) • Calculate overall ratio for each transmission gear. • Ring and pinion axle ratio swap analysis (e.g. 3.73 vs 4.10 vs 4.56). • 4x4 Crawl Ratio Calculator: Incorporates transfer case low-range and transmission first gear for rock crawlers and overland rigs. ■ GEAR SPEED MATRIX & SHIFT POINTS • Speed table across all gears from 1,000 RPM up to engine redline. • Easily analyze gear stepping, shift points, and maximum speed in each gear. ■ TIRE SIZE CALCULATOR & SPEEDOMETER CALIBRATION • Supports Metric tire sizes (e.g. 215/40R18, 265/70R17.5) and Flotation Inch sizes (e.g. 33x12.50R17, 35x12.50R17). • Full decimal wheel diameter support including 17.5-inch wheels. • Side-by-side tire comparison: diameter, circumference, revs per mile, sidewall height, and speedometer calibration (error percentage). ■ SHIFT RPM & GEAR SPACING • Analyze engine RPM drop after upshifting from each gear. • Review step ratios and gear spacing to keep engine in the peak powerband. ■ TRANSMISSION PRESETS (74 PRESETS) • 74 transmission presets from top manufacturers and performance applications. • Manual, automatic, and dual-clutch boxes (TREMEC, ZF, Ford, GM, Toyota, Honda, Hyundai, BMW, Porsche, etc.). • Quick 1-tap setup with realistic factory gear ratios. ■ MULTI-VEHICLE GARAGE PROFILES • Save and manage multiple vehicle profiles with custom tire specs, axle ratios, and transmission gear ratios. • Load any saved vehicle directly into the What If? simulator or individual calculators. ■ SPROCKET / TOOTH COUNT CALCULATOR • Motorcycle and chain-drive ratio calculator for front and rear sprockets. • Calculate sprocket tooth changes and target drive gearing. ■ OFFLINE & UNIT SUPPORT • Instant calculations with zero latency — works 100% offline. • Seamless 1-tap toggle between Metric (km/h, mm, revs/km) and Imperial (mph, inches, revs/mile). ■ BUILT FOR ALL MOTORSPORTS & BUILDS: - Drag Racing & Track Days: Dial in gear ratios, shift drop RPM, and finish line trap speeds. - Trucks & Off-Road 4x4: Re-gear ring and pinion differentials after installing larger 33", 35", or 37" tires. - Engine & Transmission Swaps: Verify drivetrain compatibility and highway cruising speeds. - Speedometer Calibration: Correct speedometer offset and tachometer readings after wheel modifications. Eliminate guessing from your automotive gearing projects. Download Gear Ratio & Speed Calculator now and simulate your drivetrain with total precision! Privacy Policy: https://domilabs.vercel.app/gear-ratio-calculator/privacy