A chess board has eight files, lettered a to h from White's left, and eight ranks, numbered 1 to 8 from White's side. Every square is named by its file then its rank, so the White king starts on e1 and the Black queen on d8.
Every notation system in chess rests on one idea: each of the sixty-four squares has a unique two-character name. Learn how the names are built once and file, rank and diagonal all become readable at a glance.
Files run up and down
A file is a vertical column of eight squares. Files are lettered a through h, counting from White's left to White's right. That means the a-file is the queenside edge of the board and the h-file is the kingside edge, from White's point of view.
Ranks run side to side
A rank is a horizontal row of eight squares, numbered 1 to 8 starting from White's side. Rank 1 is White's back rank, rank 8 is Black's.
The result is that a square name is simply a file letter and a rank number together. e1 is the intersection of the e-file and rank 1. There is no other square with that name.
The starting position, piece by piece
| Square | Piece at the start |
|---|---|
| a1, h1 | White rooks |
| b1, g1 | White knights |
| c1, f1 | White bishops |
| d1 | White queen |
| e1 | White king |
| a8, h8 | Black rooks |
| b8, g8 | Black knights |
| c8, f8 | Black bishops |
| d8 | Black queen |
| e8 | Black king |
| a2 to h2 | White pawns |
| a7 to h7 | Black pawns |
Why the letters start at White's left
The convention is fixed from White's perspective and never changes, no matter which way the board is displayed. When a board is flipped to show Black's point of view, a1 appears in the top right rather than the bottom left, but a1 is still a1.
This is why a flipped board can be disorienting for a beginner: the names are stable while the picture is not. Reading a coordinate, not a location on screen, is what keeps notated moves unambiguous.
Diagonals
A diagonal is a line of squares of the same colour, running at forty-five degrees. Diagonals do not have a single standard name, but they are usually described by their endpoints, so the long light diagonal from a1 to h8 is called the a1-h8 diagonal. Bishops live on diagonals, which is why the squares of one colour are sometimes called that bishop's squares.
The board's own coordinates
Printed diagrams and most software label the files along the bottom edge and the ranks along the left edge. Physical boards often carry the same labels, either printed on the border or written on the a1 corner square and the h8 square.
When you can switch coordinates on and off in an analysis board, the labels should follow the board orientation, so the bottom-left square is named correctly whether you are viewing from White's side or Black's.
Reading coordinates in practice
- e4, d4, c4 and the other central squares sit in the middle four files, which is why they matter so much in the opening.
- f7 and f2 are the weakest points at the start of the game, defended only by the king, which is why early attacks so often target them.
- The seventh rank is where rooks love to arrive, since it is packed with unmoved enemy pawns.
- b1 to h7 is the diagonal a fianchettoed bishop aims along.