About CarSpecsHQ

CarSpecsHQ is a reference for car specifications that are hard to find in one place. The tire-size pages compute every dimension from the size code with the standard industry geometry (ETRTO/TRA conventions): sidewall = width × aspect ratio, diameter = rim + two sidewalls. Real tires vary by brand by a few tenths of an inch — the manufacturer's spec sheet has the exact figure.

Machine-readable data: /api/sizes.json and /llms.txt.

CarSpecsHQ is free. Questions: hello@carspecshq.com.