About RunSized
RunSized is a community-built database of running shoe sizing data.
We exist because running shoe sizing is genuinely broken. Every brand fits differently. Every model within a brand fits differently. Shoe size charts don't tell you whether the Hoka Clifton runs long or whether the Nike Pegasus fits narrow. Reddit does — buried in threads that are hard to search.
RunSized collects those data points in one place. Runners submit what they bought and how it fit. That data becomes the answer to “what size should I order?”
How we started
We began by extracting sizing data from thousands of Reddit posts and running review sites. That gave us a starting dataset. Every submission from a real runner makes it more useful. The goal is simple: no runner should have to guess their shoe size.
Privacy
We collect only what you choose to share — your shoe preferences and sizing. No tracking beyond what Vercel and Supabase require to run the site. No selling data. Full details in our privacy policy (coming soon).
Who built this
Built by a runner in Sydney, Australia. If you have questions, feedback, or want to help build RunSized, reach out via the submit page.