Car Tools And Calculators
Small tools that answer one question well. Nothing you type is stored.
Each tool page shows how it calculates and when it was last checked
All tools
12 V Battery Voltage CheckRead what your 12 V battery voltage means: state of charge at rest, voltage while starting and the charging voltage with the engine running.Car Unit ConverterConvert the units you meet in car specifications: distance, volume, pressure, power, torque, temperature and fuel economy.Complaint TimelineSee how many owner complaints were filed with NHTSA for each model year of a model, and which components they named most.Cost Of Ownership CalculatorAdd up what a car costs over the years you keep it: value loss, fuel or electricity, insurance, tax, maintenance and other costs.EV Charging CalculatorWork out the energy, time, cost and range of an electric car charging session from battery size, charge levels and charger power.Fault Code ComparisonCompare two OBD-II fault codes: meaning, risk, system and possible causes, with the causes they share marked.Fault Code LookupType an OBD-II code from your scanner to open its meaning, risk and causes.Fuel Cost CalculatorWork out the fuel used and the cost of a trip from distance, consumption and fuel price.Model ComparisonPut two models side by side: model years, markets, engines and gearboxes, EU type-approval data and owner complaints.OBD Readiness And Freeze Frame GuideUnderstand the readiness monitors your scanner shows and read the freeze frame data saved with a fault code.Recall CheckerFind the official safety recalls on file for a model and model year, with a link to each official record.Roadside Safety AssistantClear, ordered steps for the moments that matter: breakdown, flat tyre, accident, overheating, smoke or fire, a red warning light or a car that will not start.Symptom CheckerPick what you notice and the closest symptom to see the questions that narrow it down, the possible causes and the risk.Tyre Size CalculatorCompare two tyre sizes: overall diameter, sidewall height, circumference and the effect on the speedometer.Used Car Inspection ChecklistA step-by-step checklist for viewing a used car: papers, body, interior, engine bay, test drive and after the drive.VIN DecoderDecode a 17-character vehicle identification number: structure, model year code, check digit and the details NHTSA holds.Warning Light FinderFind a dashboard warning light by its colour and the system it belongs to, then open its page.
How tools are checked Every tool is checked against known values before it is published, and each page explains how it calculates.