Tools
Car Tools & Calculators
Accurate calculators built on established engineering formulas — no made-up data.
Advanced tools
Finance (7)
Car Loan Payment Calculator
Compute the monthly payment and total interest from price, down payment, rate and term.
Vehicle Depreciation Calculator
Estimate residual value after a number of years at a yearly depreciation rate.
Total Cost of Ownership
Add payment, fuel, insurance and maintenance to see the real monthly and yearly cost.
Lease Payment Calculator
Compute a monthly lease payment from price, residual value and money factor.
Lease vs Buy Comparison
Compare the real cost of buying versus leasing over the same term.
Negative Equity Calculator
See whether your car is worth less than the loan balance and when it breaks even.
Insurance Premium Estimator
Estimate comprehensive insurance premium from value, age, claims history and deductible.
Performance (12)
Horsepower & Torque Converter
Convert torque to power at a given rpm using hp = torque x rpm / 5252.
Quarter Mile Estimator
Estimate quarter-mile time and trap speed from weight and power using the Wallace formulas.
Safe Towing Capacity Calculator
Check whether trailer weight stays within your vehicle's safe limits.
0-100 km/h Acceleration Estimator
Estimate acceleration time from power, weight and drivetrain.
Differential Gear Ratio Calculator
Compute final drive ratio from ring and pinion teeth and its effect on rpm.
Power-to-Weight Ratio Calculator
Compare cars by power per tonne and per kg with an acceleration estimate.
Dyno Correction Factor Calculator
Correct measured power for temperature, pressure and humidity (SAE style).
Fuel Pump Sizing Calculator
Compute required pump flow (L/h) for a target power and fuel type.
Intercooler Sizing Calculator
Estimate intercooler core volume and expected cooling efficiency.
Clutch Torque Capacity Calculator
Check whether a clutch can hold engine torque after modifications.
Speedometer Error Calculator
Compare speedometer reading with GPS speed to find the error and odometer drift.
Shift RPM Drop Calculator
Find engine rpm after an upshift and whether it stays in the torque band.
Engine (8)
Engine Displacement Calculator
Compute displacement in litres from bore, stroke and cylinder count.
Compression Ratio Calculator
Compute compression ratio from swept volume and combustion chamber volume.
Turbo Boost Pressure Ratio
Compute pressure ratio and expected power gain at a given boost level.
Fuel Injector Size Calculator
Size injectors for a target power from cylinder count and duty cycle.
Engine Airflow (CFM) Calculator
Compute required airflow at a given rpm and volumetric efficiency.
Spark Plug Gap Converter
Convert spark plug gap between mm and inches and sanity-check the spec.
Valve Clearance Shim Calculator
Compute the shim thickness needed to reach target valve clearance.
Drive Belt Length Calculator
Compute approximate belt length between two pulleys and their speed ratio.
Drivetrain (1)
Tires (6)
Tire Size & Speedometer Error
Compare a new tire size with stock to see diameter difference and speedometer error.
Tire Pressure vs Temperature
Tire pressure changes with temperature; compute expected pressure at another temperature.
Tire Life Calculator
Estimate remaining tire distance and cost per km from tread depth.
Wheel Offset Calculator
Compute inner and outer clearance change when altering wheel width or offset.
Tire Rotation Due Calculator
Work out the next tire rotation in kilometres and expected days.
Tire Wear Rate Calculator
Measure tread wear per 10,000 km and remaining distance to the wear limit.
Fuel (6)
Fuel Savings Comparison
Compare two vehicles' consumption to see monthly and yearly fuel savings.
CO2 Emissions Calculator
Compute your car's emissions from petrol use (2.31 kg per litre).
Octane Blend Calculator
Compute the resulting octane when blending two fuel grades.
Idling Fuel Waste Calculator
Compute how much fuel and money idling wastes each year.
Fuel Tank Range Calculator
Estimate range from your current tank level plus a safe reserve distance.
Fuel Cost per Passenger
Split trip fuel cost across passengers to see each person's share.
Trips (2)
Converters (5)
Fuel Economy Converter
Convert between L/100km, US MPG, UK MPG and km/L.
Torque Unit Converter
Convert torque between Nm, lb-ft and kg-m for fastener specs.
Pressure Unit Converter
Convert tire and oil pressure between psi, bar and kPa.
Speed Unit Converter
Convert speed between km/h, mph, knots and m/s.
Temperature Converter
Convert engine and oil temperatures between Celsius, Fahrenheit and Kelvin.
Safety (1)
Maintenance (10)
Coolant Mix Calculator
Compute concentrate and distilled water needed for a target mix ratio.
Oil Change Interval Calculator
Estimate your next oil change based on oil type, driving conditions and heat.
Oil Quantity & Cost Calculator
Compute full oil change cost including filter, labor and cost per km.
Brake Pad Life Calculator
Estimate remaining distance before brake pads need replacing.
Cooling System Capacity Calculator
Compute water and coolant volumes for a system flush, plus cost.
A/C Refrigerant Charge Calculator
Compute refrigerant and compressor oil charge plus service cost.
Timing Belt Due Calculator
See how much is left before the timing belt is due, by distance and by age.
Brake Rotor Life Calculator
Compare rotor thickness to the discard limit and estimate remaining life.
Transmission Fluid Change Calculator
Compute ATF volume for a drain-and-fill or full flush plus cost.
Brake Fluid Change Due Calculator
Decide when to change brake fluid based on age and measured moisture.
Electrical (8)
Battery Runtime Calculator
Estimate how long a battery sustains a given electrical load.
Battery CCA Requirement Calculator
Compute required cranking amps from engine size, fuel type and climate.
Alternator Load Calculator
Check alternator headroom after adding audio, lighting or a fridge.
Wire Gauge & Fuse Calculator
Pick the right wire gauge and fuse from current, run length and voltage drop.
Car Battery Charging Time Calculator
Compute charging time from capacity, state of charge and charger current.
Automotive Voltage Drop Calculator
Check voltage drop on 12 V runs to pick a safe wire gauge.
Solar Trickle Charger Sizing
Size a solar panel to offset parasitic battery drain while parked.
Parasitic Battery Drain Calculator
Work out how many days until no-start from a parasitic draw while parked.
Load & Towing (2)
Electric (5)
EV Charging Time Calculator
Compute charging time from current to target state of charge at a given charger power.
EV Running Cost Calculator
Compute electricity cost per 100 km, per month and per year.
EV vs Petrol Comparison
Compare monthly costs of an EV and a petrol car, and when the price gap pays back.
EV Battery Degradation Calculator
Estimate remaining pack capacity and range after years of use.
EV Home Charger Cost Calculator
Compare home charger installation cost against savings versus public charging.
Repair (2)
Workshop (4)
Labor Hours & Invoice Calculator
Build a workshop invoice from labor hours, hourly rate, parts and VAT.
Workshop Profitability Calculator
Compute margin and monthly break-even for a repair shop.
Torque Spec Converter
Convert fastener torque between Nm, lb-ft, lb-in and kgf-m.
Torque Wrench Extension Calculator
Compute the correct wrench setting when using a crowfoot or offset adapter.
Buying (3)
Car Import Cost Calculator
Compute landed cost of importing a car: shipping, customs duty, VAT and inspection.
Extended Warranty Value Calculator
Compare extended warranty price against expected repair costs.
Trade-In Value Estimator
Estimate your car's trade-in or private sale value from age, mileage and condition.