Twenty-five letters · Four groups · One stem
Twenty strokes on a stem. Read from root to crown.
How it works
Every Ogham letter is built from notches and strokes laid across a central line called the flesc. On standing stones this line was the edge of the stone itself — the corner became the stem, and the letters were carved either side of it.
The twenty-five letters are divided into four groups called aicmí (singular: aicme), each named after its first letter. A fifth group — the forfeda — was added later to represent sounds that came into Irish through borrowing from Latin and Norse.
Direction matters. Classical Ogham on stone reads from the bottom of the stem upward — you place your finger at the base of the stone and follow the strokes toward the sky. In manuscripts and in modern use, Ogham is written horizontally, left to right, which is the convention used throughout this site.
The letter names are drawn from the natural world — trees, plants, and shrubs familiar to early Irish people — giving the alphabet a particular character: rooted, seasonal, alive.
Read bottom to top. Found on standing stones across Ireland and Britain. The stone's edge forms the stem.
Read left to right. Used in manuscripts from the 7th century onward and in all modern contexts.
The letters
Hover any letter to see its full name. The stem colour indicates its group.
Missing letters
Classical Ogham was designed for Old Irish — a language that simply did not use certain sounds that are common in modern English. The letters J, K, P, V, W, X, Y, and Z either did not exist in Irish phonology, or were so rare that no dedicated Ogham character was ever created for them. The NG combination is a special case — Ngeadal exists in the classical alphabet for exactly this sound.
This is not a flaw — it reflects the fact that Ogham was built for one language and later borrowed by others. When we transliterate modern English into Ogham we are doing something historically unusual: using an ancient Irish script to represent sounds it was never designed to carry.
The substitutions below follow the most widely accepted modern scholarly convention — matching each missing letter to its closest phonetic equivalent in the classical alphabet. Where a sound has no single match, a compound of two letters is used. These substitutions are shown clearly whenever they are applied, so nothing is hidden.
Each missing English letter mapped to its Ogham equivalent, with the reason why.
Ogham in the digital world
Every letter, symbol, and script in the world's computing systems is assigned a unique number by the Unicode Consortium — a non-profit body that maintains the global standard. In 1999, Ogham became part of that standard: 29 characters assigned to codepoints U+1680 through U+169C, covering all twenty original letters, the six Forfeda, a space mark, and a feather mark for stone edges. Every phone, computer, and web browser on earth now carries Ogham.
Getting there was not straightforward. The proposal was first submitted in 1994 by Michael Everson, an American-born linguist and typographer working in Dublin who had made it his mission to get minority scripts into Unicode. The Ogham proposal was initially resisted — one influential voice on the Unicode committee argued the script was too obscure and historically limited to warrant inclusion. Everson persisted, revised the proposal, and secured approval. The block was formally encoded in Unicode 3.0.
The Forfeda are included in full. This matters because it means the complete medieval alphabet — not just the classical twenty — is part of the permanent digital record. The Font Lab on this site uses fonts built on these codepoints, so when you switch between typefaces you are switching between different designers' interpretations of the same underlying Unicode characters.
The block contains 29 assigned codepoints. The first (U+1680) is the Ogham space mark — a special space used between words in Ogham text, distinct from a regular space. The final assigned point (U+169C) is the Ogham feather mark right, used to indicate the edge of a stone in transcriptions.