The site is run by Hugo Miggels. The fastest way to reach him is email: hello@inflationcalculator.com.
Corrections
Spotted a wrong number, a broken link, or a claim without a source? Say which page and what's wrong, and it gets fixed. Data corrections appear in the public update log.
Press and citations
You're welcome to cite any page without asking; the methodology explains how results are computed and how to attribute them. For questions about the data or custom breakdowns, email with your deadline and what you need.
Everything else
Ideas, feedback on the calculator, and notes about what's missing are all read and appreciated. This is an independent project, so replies can take a day or two.