Automotive

Tire Size Conversion Calculator

Convert metric tire sizes (205/55R16) to sidewall height, overall diameter, circumference, and revolutions per mile. Works for any standard tire code.

Speedometer Error Calculator

Calculate speedometer error from a tire size change. Enter original and new tire dimensions to find your true speed and how much the reading is off by.

Speedometer Gear Calculator

Calculate vehicle speed from RPM, gear ratio, axle ratio, and tire diameter. Use it for speedometer calibration, custom tire fitments, and axle ratio swaps.

Tire Size Comparison Calculator

Compare two tire sizes and see the difference in diameter, circumference, and speedometer effect. Enter both tire codes to get a full dimensional comparison.

Annual Commute Cost Calculator

Calculate true yearly commute cost from gas, tolls, parking, vehicle wear, and time value. See what your job actually costs you to get to.

Used Car vs New Car 5-Year Cost Comparison

Compare 5-year total cost of a new vs used car including depreciation, financing, insurance, repairs, and resale. See real ownership cost.

DIY Oil Change Annual Savings Calculator

Calculate how much you save changing your own oil vs the dealer or quick lube. Inputs oil quarts, filter cost, shop price, and time value.

Tire Cost Per Mile Calculator

Calculate the per-mile cost of any tire from price, mounting, and tread life. Compare cheap to premium tires on real cost, not sticker price.

Engine Compression Ratio Calculator

Calculate engine compression ratio from bore, stroke, chamber volume, head gasket, and deck clearance. Includes displacement and octane requirement.

Gas Oil Ratio Calculator (2-Stroke)

Calculate 2-stroke oil and gas mix for any ratio: 50:1, 40:1, 32:1, and 25:1. For chainsaws, dirt bikes, outboard motors, and all 2-stroke engines.

Horsepower and Torque Converter

Convert between horsepower and torque at any RPM. Calculate peak power from torque curves and understand the HP, torque, and engine speed relationship.

Quarter Mile ET Calculator

Calculate quarter-mile elapsed time and trap speed from vehicle weight and horsepower using Hale's formula. Includes drivetrain loss and altitude correction.

Skid Speed Calculator

Calculate vehicle speed from skid marks using the NHTSA friction formula for accident reconstruction. Enter skid length, road surface, and braking efficiency.

Turbocharger Boost Pressure Calculator

Calculate turbocharger boost pressure, pressure ratio, and power gain. Converts between psi, bar, and kPa and estimates compressor outlet temperature.

Wheel Load and Corner Weight Calculator

Calculate the load on each wheel from vehicle weight, wheelbase, track width, and CG height. Returns corner weights, front/rear bias, and oversteer tendency.

Quarter Mile ET Calculator

Estimate your car's quarter mile elapsed time (ET) and trap speed from horsepower and weight. Used for drag racing planning and vehicle performance comparison.

Torque Wrench Extension Calculator

Calculate adjusted torque setting when using a crow's foot or extension on a torque wrench. Accurate ft-lbs and Nm results.

Antifreeze Mix Ratio Calculator

Calculate the correct antifreeze to water ratio for your climate. Find freeze and boil-over protection for any coolant concentration.

Battery Cold Cranking Amps Calculator

Calculate minimum Cold Cranking Amps from engine displacement, climate zone, and battery age. Returns the CCA rating for reliable cold weather starting.

Brake Pad Life Remaining Calculator

Estimate how much brake pad life you have left and when you need to replace them based on current thickness and driving habits.

Cabin Air Filter Replacement Calculator

Calculate when to replace your cabin air filter based on mileage, age, and driving environment. Improve air quality and HVAC performance in your vehicle.

Car Battery Charge Time Calculator

Calculate how long it will take to charge a car battery based on capacity (Ah), charger output (amps), and current state of charge.

Car Wash Savings Calculator (DIY vs Professional)

Calculate how much you save washing your car at home vs. paying for a professional car wash. See annual savings and break-even point for equipment.

Car Wax Schedule Calculator

Find your car waxing frequency from climate zone, parking type, and wax product. Returns recommended interval for carnauba, liquid wax, and paint sealant.

Coolant Freeze Point Calculator

Calculate the freeze and boil protection of your coolant mixture. Find the right antifreeze concentration for your climate.

Dashboard Warning Light Guide

Look up any dashboard warning light by color and symbol shape. Returns meaning, urgency level, whether to pull over or schedule service, and common causes.

Engine Compression Ratio Calculator

Calculate engine compression ratio from bore, stroke, deck height, head gasket, and combustion chamber volume. Essential for engine builds.

EV Charging Cost Calculator

Calculate the cost to fully charge an electric vehicle at home or at a public charger. Compare charging costs to the equivalent cost of gasoline.

Fuel Injector Size Calculator

Calculate fuel injector size in cc/min and lb/hr from target HP, cylinder count, and duty cycle. Covers gasoline and E85 with minimum and maximum flow rates.

Fuel Octane Selection Guide

Determine the correct octane rating for your vehicle. Find out if premium is required or optional and calculate the annual cost of premium vs regular.

Fuel Range Remaining Calculator

Calculate exactly how far you can drive on your remaining fuel. Enter fuel level, tank size, and fuel efficiency to get your range.

Gas vs Hybrid Savings Calculator

Calculate how long it takes for a hybrid car to pay for itself versus a gas car. Compare fuel costs, purchase price difference, and break-even mileage.

Headlight Aim Height Calculator

Calculate the correct headlight aim height for any vehicle and distance. Properly aimed headlights improve safety and avoid blinding other drivers.

Monthly Car Depreciation Calculator

Calculate monthly and annual car depreciation from purchase price, vehicle age, and mileage. See the true ownership cost beyond your monthly loan payment.

MPG to L/100km Converter

Convert fuel efficiency between US MPG, UK MPG, and L/100km instantly. Includes km/L and miles per liter with comparison to average new car ratings.

Oil Viscosity Selector

Find the right engine oil viscosity from climate, driving style, and engine age. Explains SAE grades from 0W-20 to 20W-50 and synthetic vs conventional.

Parking Space Size Calculator

Calculate the dimensions needed for a parking space based on vehicle size and parking angle. Get standard dimensions in metric and imperial.

Spark Plug Gap Calculator

Find the correct spark plug gap for your engine type and ignition system. Understand how gap size affects combustion, power, and fuel economy.

Stopping Distance Calculator

Calculate total stopping distance by speed, road condition, and reaction time. Understand the difference between thinking distance and braking distance.

Tire Life Estimate Calculator

Estimate how many miles or kilometers your tires will last based on tread depth, wear rate, and driving conditions. Know when to start budgeting for new tires.

Tire Load Index Calculator

Decode your tire load index number to find the maximum weight each tire can carry. Verify your tires are rated for your vehicle and cargo weight.

Tire Wear Estimator

Estimate remaining tire life from tread depth, driving style, and road conditions. See when to replace tires before reaching the legal wear limit.

Trailer Tongue Weight Calculator

Calculate safe trailer tongue weight for towing. Find the ideal tongue weight percentage (10–15%) and check if your hitch and vehicle can handle the load.

Transmission Fluid Change Interval Calculator

Find when to change transmission fluid from vehicle type and driving conditions. Returns interval in miles for automatic, manual, and CVT transmissions.

Wheel Alignment Check Interval Calculator

Calculate when your next wheel alignment is due based on mileage, driving conditions, and last alignment date. Prevent uneven tire wear and handling issues.

Wheel Offset Calculator

Calculate wheel offset (ET), backspacing, and centerline from rim width and hub distance. See how positive and negative offset affects stance and clearance.

Windshield Repair vs Replace Calculator

Determine whether your cracked or chipped windshield can be repaired or needs full replacement. Based on damage size and location.

Wiper Blade Size Guide Calculator

Find the correct wiper blade size for your vehicle. Learn how to measure wiper blades and choose the right replacement type.

Road Trip Stops Calculator

Plan road trip rest and fuel stops from total distance, average speed, and tank range. Returns a timed stop schedule with fuel amounts and arrival time.

Antifreeze Mix Ratio Calculator

Calculate the ideal antifreeze-to-water ratio for your climate. A 50/50 mix protects to -34F; 70/30 mix to -84F. Returns freeze and boil-over protection.

Auto Loan Refinance Calculator

Calculate monthly savings and total interest saved by refinancing your car loan at a lower APR or shorter term. Compares your current loan to a new offer.

Brake Pad Life Estimator

Estimate how long your brake pads will last based on driving style, mileage, and conditions. Plan replacement before they wear out.

Brake Pad Life Estimator

Estimate brake pad life and replacement mileage from current thickness, driving style, and annual miles. Alerts when pads are below the safe 3mm minimum.

Coolant Mix Ratio Calculator

Calculate the antifreeze-to-water mix ratio for your climate. Returns freeze protection to -34°F and boil point to 265°F for 50/50, 60/40, and 70/30 blends.

Engine Horsepower Calculator

Estimate engine horsepower from quarter-mile elapsed time and vehicle weight. Returns wheel HP and estimated crank HP using the ET drag racing method.

Fuel Cost Trip Calculator

Estimate road trip fuel cost from distance, fuel efficiency, and gas price. Supports MPG, km/L, and L/100km with total cost and per-mile fuel breakdown.

Fuel Economy Calculator

Calculate actual MPG, km/L, or L/100km from odometer readings and fuel receipts. Track fuel economy across multiple fill-ups to spot efficiency trends.

MPG to L/100km Converter

Convert between US MPG, UK MPG, and L/100km using MPG = 235.2 / L100km. Returns all three values with annual fuel cost at your local fuel price.

Oil Change Interval Calculator

Calculate when your next oil change is due based on oil type, driving conditions, and mileage. Track your maintenance schedule.

Tire Pressure Temperature Adjustment Calculator

Calculate tire pressure change with temperature via Gay-Lussac Law. Enter cold PSI and temp difference to get hot PSI for summer, winter, and track conditions.

Transmission Fluid Calculator

Determine transmission fluid change interval from vehicle type, mileage, driving conditions, and fluid type. Auto: 30k-60k miles. CVT: 30k-40k miles.

Wheel Alignment Angle Calculator

Look up wheel alignment specs for toe, camber, and caster. Enter measured angles to check factory tolerances and get guidance on symptoms and corrections.

Windshield Wiper Size Calculator

Find wiper blade sizes for driver, passenger, and rear positions from vehicle year, make, and model. Covers hook, pinch-tab, and side-pin connection types.

Wiper Blade Size Finder

Find correct wiper blade sizes by year, make, and model. Returns driver, passenger, and rear blade lengths with beam versus conventional blade recommendations.

Car Value Estimator

Estimate your car's current market value from age, mileage, and condition in miles or km. Quick rough estimate for private sale or trade-in pricing.

Compression Ratio Calculator

Calculate engine compression ratio from bore, stroke, deck clearance, and chamber volume. Helps determine octane requirements and engine performance potential.

Engine Displacement Calculator

Calculate engine displacement in cc, cubic inches, and liters from bore, stroke, and cylinder count. Useful for engine builds, tuning, and comparing specs.

Hybrid vs Gas Savings Calculator

Compare annual and 5-year fuel costs between a hybrid and gas vehicle. See how much you could save by switching to a hybrid.

Tire Rotation Schedule Calculator

Calculate when your next tire rotation is due from current and last-rotation mileage. Stay on schedule with a 5,000 to 7,500 mile recommended rotation interval.

Torque Wrench Extension Calculator

Calculate the corrected torque wrench setting when using an extension or crow's foot adapter. Enter torque spec and extension length for the safe reading.

Total Car Ownership Cost Calculator

Calculate the true total cost of owning a car including purchase price, fuel, insurance, maintenance, and depreciation over time.

0-60 MPH Calculator

Estimate your car's 0 to 60 mph acceleration time from horsepower and curb weight. Uses the power-to-weight formula with real-world correction factors.

Annual Car Cost Calculator

Calculate the true total annual cost of owning your car. Include fuel, insurance, maintenance, loan payments, and registration for a complete picture.

Auto Paint Calculator

Calculate how much automotive paint you need based on car size and number of coats. Get accurate estimates in quarts or liters.

Braking Distance Calculator

Calculate total stopping distance based on speed, road conditions, and reaction time. Supports both metric and imperial units.

Car Battery CCA Calculator

Find recommended Cold Cranking Amps (CCA) from engine displacement and climate zone. Returns minimum CCA rating for reliable cold-weather starting at 0°F.

Car Depreciation Calculator

Estimate your car's current market value from purchase price, age, and mileage using standard depreciation curves. See how value changes each year.

Car Lease Calculator

Calculate monthly car lease payment from MSRP, capitalized cost, residual value, money factor, and lease term. Returns depreciation and finance charge.

Car Loan Calculator

Calculate your monthly car loan payment. Enter vehicle price, down payment, interest rate, and loan term to estimate your payments.

Car Loan Early Payoff Calculator

Calculate time and interest saved by making extra car loan payments. Enter balance, rate, and extra monthly payment to see payoff date and total savings.

Car Wash Savings Calculator

Compare annual DIY car washing versus professional car washes and detailing. Enter wash frequency and prices to see yearly spend and savings for each method.

Coolant Mix Ratio Calculator

Calculate how much coolant to drain and add to achieve your desired antifreeze-to-water ratio. Enter system capacity, current ratio, and target ratio.

Engine Horsepower Calculator

Estimate horsepower from quarter-mile ET and weight using HP = weight / (ET/5.825)³. Also calculates from torque and RPM using HP = (torque × RPM) / 5252.

EV Range Calculator

Estimate your EV's remaining range from battery capacity, energy consumption in Wh/mile or Wh/km, and current state of charge. See realistic range under load.

Fuel Efficiency Calculator

Calculate your vehicle fuel efficiency in MPG or km/L. Enter distance driven and fuel used to find out how efficient your car really is.

Fuel Savings Calculator

Compare annual fuel costs between two vehicles by MPG and price per gallon. See yearly savings, monthly savings, and payback period when upgrading efficiency.

Fuel Tank Range Calculator

Calculate how far you can drive on a full tank. Enter your tank size and fuel efficiency to find your maximum driving range.

Gas vs Electric Cost Calculator

Compare annual fuel costs between a gas-powered car and an electric vehicle based on your driving habits and local energy prices.

Gear Ratio / RPM at Speed Calculator

Calculate engine RPM at any speed based on tire diameter, final drive ratio, and transmission gear ratio. Essential for drivetrain tuning.

Monthly Car Payment Calculator

Calculate monthly car loan payment from vehicle price, trade-in, down payment, APR, and term. Shows total interest and amortization for 24 to 84 months.

MPG Comparison Calculator

Compare annual fuel cost for two vehicles from MPG, miles driven, and gas price. Returns yearly savings, 5-year savings, and break-even on efficient upgrades.

Oil Change Interval Calculator

Calculate next oil change mileage from last service and oil type. Compares conventional (3k-5k mi), synthetic blend, and full synthetic (7.5k-15k mi).

Parking Cost Calculator

Calculate total parking cost from hourly or daily rates and duration. Compare pay-as-you-go versus monthly pass to find break-even days.

Road Salt / Deicer Calculator

Calculate how many bags of road salt or deicer you need for your driveway, walkway, or parking area based on area and application rate.

Road Trip Time Calculator

Plan road trip travel time from distance, speed, and scheduled stops. Includes fuel stop intervals, rest breaks, and estimated arrival time.

Speedometer km/h to mph Converter

Quickly convert between kilometers per hour and miles per hour. Includes common speed references for driving in different countries.

Tire Pressure Adjustment Calculator

Calculate tire pressure change with temperature using the ideal gas law. Enter PSI and temperature difference to find the correct inflation adjustment.

Tire Size Comparison Calculator

Compare two tire sizes to see diameter difference, speedometer error, and ride height change. Enter old and new tire sizes in standard format.

Towing Capacity Calculator

Calculate your remaining towing capacity after accounting for passengers and cargo. Enter GVWR and curb weight to find safe towing limits.

Trailer Tongue Weight Calculator

Calculate safe tongue weight from total trailer weight. Returns the safe 10-15% range and checks against your vehicle's hitch and tow rating limits.

Windshield Washer Fluid Mix Calculator

Calculate the correct washer fluid concentrate-to-water ratio for your tank size and freeze protection level. Works for temperatures down to -40 degrees.

Wiper Blade Size Guide

Find the correct wiper blade sizes for your vehicle by selecting your vehicle type and checking driver and passenger side dimensions.