1. Home
  2. /
  3. Tools

Free auto shop calculators

VIN decode, engine size, tire equivalents, SAE to metric wrenches, and torque conversions for salvage-yard and DIY work. All free, no account required.

Free VIN decoder

Paste a 17-character VIN to look up year, make, model, engine, body style, and plant from the public NHTSA vPIC catalog. Use it at a salvage yard to confirm what a vehicle actually is before you pull parts.

Open converter

Liters to cubic inches converter

Convert liters to cubic inches the way yards and listings talk. 5.7 L is 350 cid on a Chevy small-block and 345 cid on a Hemi. Type either unit and see the exact math plus common shop names.

Open converter

Tire size calculator

Decode a sidewall code like 225/45R17 into section width, sidewall height, overall diameter, and revolutions per mile. Then compare close equivalents that stay within 3% diameter — same rim first, which is what you want for a wheel already in the yard.

Open converter

SAE to metric wrench conversion chart

Convert standard inch wrenches and sockets to millimeters, then see whether the closest size will actually fit. A 7/16" wrench is close to 11 mm. A 3/8" wrench on a 10 mm fastener is a mismatch that can round the corners.

Open converter

ft-lb to Nm torque converter

Convert torque between ft-lb, N·m, in-lb, and kgf·m. Type in any box and the others follow. Use it when a shop manual, torque wrench, and fastener spec are not in the same unit.

Open converter

Weeks between dates calculator

Pick a date in the past and the date of an event. The calculator shows the same span as years, months and weeks, total weeks, and exact days — useful for how long a vehicle sat, a listing age, or any two calendar dates.

Open converter

Need parts, not a calculator? Search junkyards by ZIP.