Size 3, 5 or 6: Understanding King Height and Square Size

Size 5, size 6

A commercial numbering of chess sets by king height, from 1 (the smallest) to 7 or more. Size 5 corresponds to a king of about 8.5 to 9.5 cm. It is not a standard: the exact heights vary from one maker to another, which is why it is important to check the height in millimetres.

Size 5 wooden chess pieces: what the numbers really say

Size numbers are a habit of makers, notably in France, not an official standard. Two “No. 5” sets from different brands can have kings of 8.5 cm and 9.5 cm. The only reliable landmark is therefore the king height, ideally supplemented by the diameter of its base. The table below gives the most common correspondences.

Indicative values taken from makers’ and sellers’ listings; they vary from one brand to another. The base is calculated using the FIDE rule (40 to 50% of the height of the piece). Always check the actual height given in millimetres.

The FIDE standard: 95 mm for the king

FIDE has published chess equipment standards, revised in 2022 and then replaced on 1 March 2026 by a new chapter devoted to equipment without electronic components. For the competitions it organises, it sets the following heights:

The other requirements are just as useful for judging a set:

• the base diameter of each piece must be 40 to 50% of its height;
• the order of heights must be respected: king, queen, bishop, knight, rook, pawn;
• the pieces must withstand a tilt of about 30° without falling over;
• the underside must be fitted with felt or a silent, non-slip material;
• the squares measure between 5 and 6 cm on a side, and four pawns must be able to stand on one square;
• for competitions, the table measures about 110 × 85 cm, at a height of 74 cm.

These standards are aimed at official competitions. Nothing stops you from playing at home with smaller or larger pieces, provided the balance between pieces and board is respected.

Matching the pieces and the board

The practical rule follows directly from the standard: four pawns must fit on a square, which amounts to saying that the side of the square must be at least twice the diameter of a pawn’s base. Another simple rule, often quoted, holds that the square should exceed the diameter of the king’s base by about 1 cm. Too small, and the square feels cramped and makes the pieces fall; too large, and it makes the position hard to take in at a glance.

Le Palais des Échecs has published a full guide to the official dimensions of a size 5 chessboard and of the other sizes, with the overall board dimensions to allow for according to the border.

Which size to choose according to use?

• For playing at a club or preparing for tournaments: a size 5 or 6, close to the FIDE standard, on squares of 5 to 6 cm. You will find the same visual landmarks as in competition.
• For a drawing room or a coffee table: a size 5 remains the most versatile; a size 6 stands out more but calls for a board of about 50 cm.
• For travelling or for children: a size 3 or 4, lighter, on a compact board.
• For decoration: the large sizes (7 and over) impress, but become impractical for long games.

Weight matters as much as height: a large unweighted piece feels hollow. See our page on weighting chess pieces. And to understand why all these standards start from the Staunton pattern, see the history of the Staunton pattern.

Common mistakes

Buying pieces and a board separately without comparing base and square is the most common mistake: a 10.5 cm king on 4.5 cm squares gives a crowded set in which the pieces touch. Another trap: relying on the number without reading the height, or confusing the overall board dimension (border included) with the width of the squares. Finally, some listings give the king height in inches: 3.75 inches corresponds to about 9.5 cm, 4 inches to about 10.2 cm.

Sources: FIDE, Chess Equipment without Electronic Components (in force from 1 March 2026); FIDE, Standards of Chess Equipment (2022–2026).