Crochet Pattern Translator: US, UK and 4 more languages

How it works: the math behind the tool

US and UK patterns use the same abbreviations for different stitches: “dc” is a double crochet in US terms but a US single crochet in UK terms. A chain of find-and-replace operations therefore corrupts the text it has just converted.

The translator works in two passes. First, every term of the source system (45 concepts with abbreviations, full names, plurals and regional variants) is replaced by a neutral token such as __TOKEN_SC__, matching the longest terms first so that “hdc2tog” is caught before “dc”. Then each token is written out in the target system. Tokens belong to no system, so one conversion can never overwrite another.

The checker reads the tokenized pattern, so it works with any source language. Each basic stitch uses 1 stitch and makes 1, an increase uses 1 and makes 2, a decrease uses 2 and makes 1, and a magic ring with 6 stitches makes 6. Brackets with “x 6”, “around” and “rep from *” are expanded, and the total is compared with the count written at the end of the line.

Everything runs in your browser: your pattern is never sent to a server.

How the two-pass tokenizer reads a pattern

In the first pass the translator scans each line and recognises full stitch names, plurals and common aliases before short abbreviations, so “half double crochet” is never read as “double crochet”. One-letter variants are case sensitive, which keeps a French “CM” (magic circle) apart from centimetres. Numbers, brackets, asterisks and repeat counts are kept as they are.

In the second pass every recognised term is replaced by its equivalent in the target system, as an abbreviation or as a full name. Because the mapping comes from a fixed dictionary of 45 terms, the result is identical every time you translate the same text.

Why US and UK terms are one stitch apart

British and American patterns name stitches with the same words but start counting from a different point. The stitch a US pattern calls single crochet is called double crochet in the UK, a US double crochet is a UK treble, and so on up the scale. A sweater worked in UK trebles from a US pattern grows taller with every row, and an amigurumi worked one height too short loses its shape. Spanish, German, French and Brazilian patterns follow the US heights with their own words, so they translate one to one.

What the stitch count auditor checks

The auditor recounts each row or round from the stitches written in it: an increase adds one stitch, a two-together decrease removes one, and a group in brackets is multiplied by its repeat count. The result is compared with the total in parentheses at the end of the line. A mismatch usually means a typo in the original pattern or a stitch that was not recognised, and it is flagged before you crochet a single loop.

Last updated: November 3, 2026