Car tools & calculators
Use these free, no-sign-up tools to estimate EV charging cost and time, choose a sensible jump-starter size, decode a tire’s DOT manufacturing date, compare two tire sizes, or narrow an OBD2 scanner or wireless phone adapter. Each tool shows its assumptions and limitations, so the result is a decision aid rather than a promise about a specific vehicle or product.
Tools index updated .
EV charging cost & time
Battery size, your rate, and charge levels in — dollar cost, Level 1, Level 2 or DC fast charging time, and a full-charge estimate out.
OpenJump starter amp sizing
Pick your engine size and climate for a sensible peak-amp target, with the caveats that matter.
OpenTire age decoder
Enter the last four digits of the DOT code to decode when a tire was made and whether to replace it.
OpenTire size calculator
Compare two tire sizes: overall diameter and the speedometer difference between them.
OpenOBD2 scanner chooser
Separate engine-code readers, enhanced-system scanners, and bidirectional tablets in three questions.
OpenWireless adapter chooser
Check the wired-system requirement, then match CarPlay, Android Auto, or both to the ranked adapters.
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