Automotive
Fuel cost, MPG, lease, tire size · 24 tools
Fuel & MPG 3
Driving Carbon Calculator Your car's yearly CO₂ from miles and MPG, in kg, tonnes, and tree-years — EPA emission factors.
-> MPG Calculator Real fuel economy from a fill-up: MPG, L/100km, and km/L from distance and fuel used. mi/km, gal/L toggles.
-> Speeding Time Saved Calculator Time saved by driving faster over any distance — the deflating math of speeding, with fuel-cost context.
-> Ownership 16
Belt Length Calculator V-belt and drive belt length from pulley diameters and center distance — shop machines to mower decks.
-> Bolt Torque Reference General torque specs for SAE grade 5/8 and metric 8.8/10.9 fasteners in Nm and ft-lb — dry-thread values with the rules that matter.
-> Car Depreciation Calculator Estimated car value from price and age using the standard 20%-then-15% depreciation curve.
-> Car Lease Calculator Lease payment split into depreciation and finance charge — from cap cost, residual, term, and APR (auto money-factor conversion).
-> Carburetor CFM Calculator Carburetor CFM from displacement, RPM, and volumetric efficiency — the classic 3456 formula.
-> Compression Ratio Calculator Static compression ratio from swept and clearance volumes, with the pump-gas and boost rules of thumb.
-> Engine Displacement Calculator Engine size from bore, stroke, and cylinders — cc, litres, and cubic inches with in/mm toggles.
-> EV Charging Cost Calculator Cost to charge an EV: full-charge price, range, and cost per 100 miles from battery size, kWh price, and efficiency.
-> Fuel Injector Size Calculator Fuel injector sizing from horsepower, BSFC, and duty cycle — naturally aspirated and boosted, in both catalog units.
-> Gas vs Electric Car Calculator Head-to-head running costs: gas car vs EV per 100 miles and the yearly savings at your mileage and local prices.
-> Horsepower & Torque Calculator HP and kW from torque and RPM — why dyno curves always cross at 5,252 RPM.
-> Piston Speed Calculator Mean piston speed from stroke and RPM — the physics behind redlines, with street/race guidelines.
-> Pulley RPM Calculator Driven pulley RPM and drive ratio from motor speed and pulley diameters — shop machine math.
-> Quarter Mile Calculator Quarter-mile ET and trap speed from weight and horsepower — the classic cube-root drag racing formulas.
-> Repair Shop Estimate Calculator Build or sanity-check a repair estimate: labor, parts markup, and shop supplies the way shops actually quote.
-> Torque Wrench Extension Calculator The corrected torque-wrench setting when using a crowfoot or inline extension — stop over-torquing.
-> Running costs 1
Tires 4
RPM at Speed Calculator Engine RPM at any road speed from axle ratio, trans gear, and tire diameter — the classic 336 formula.
-> Tire Size Calculator Decode any tire size: overall diameter, circumference, and revs per km — compare sizes before swapping wheels.
-> Tire Size Comparison Compare two tire sizes: diameter change and true speedometer error — the ±3% rule for swaps.
-> Wheel Offset & Backspacing Calculator Convert wheel offset (ET mm) to backspacing and frontspacing inches — fitment math before you buy.
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