Free Nihonto Tools
Free reference tools for nihonto collectors, built and maintained by our team in Tokyo. Use them to read the tang of your sword, convert traditional measurements, and estimate a blade’s era — no account, no charge.
Japanese Era Converter
Convert the era name on a sword tang into a Western year — all 248 eras from 645 CE, both Nanbokuchō courts, with Kotō/Shintō/Shinshintō classification.
尺寸分 · ShakuNagasa Converter
Shaku, sun and bu to centimetres and inches — and back — with automatic legal classification as tantō, wakizashi or katana.
銘 · MeiMei Reader
Decode the signature on your sword’s tang kanji by kanji: provinces, honorary titles, clan names, smith name kanji and date formulas.
Looking for deeper reading? Our nihonto blog covers authentication, NBTHK papers, blade flaws and collecting guides — or browse the current collection, sourced and photographed by us in Japan.