Free, no-sign-up calculators and converters for everyday car maintenance — tyre pressures and sizes, torque figures and coolant mixes. Each one runs in your browser and works in metric or imperial units.
Tyre & wheel tools
🛞Non-stock tyre pressure calculatorAdjust your pressures after fitting a different tyre size or load rating.
🔄Tyre pressure converterConvert between bar, PSI and kPa instantly.
📐Tyre size comparison & speedometer errorCompare two sizes for diameter, clearance and speedo error.
🔄Tyre pressure converterConvert between bar, PSI and kPa instantly.
📐Tyre size comparison & speedometer errorCompare two sizes for diameter, clearance and speedo error.
Workshop tools
🔧Torque converterConvert Nm ⇄ lb-ft ⇄ kg-m, with common tightening figures.
❄️Coolant / antifreeze mix calculatorWork out concentrate and water for your target frost protection.
❄️Coolant / antifreeze mix calculatorWork out concentrate and water for your target frost protection.
Looking for a reset or calibration procedure for your specific car? Browse the guides by make and model.