Standard Dice Size: D6 & D20 Size Chart (mm & inches)

D6 size is usually the length of a cube’s edge, not its corner-to-corner diagonal. A D20 can be described across opposite faces or point to point, so confirm the measurement convention. Size affects readability, feel, shipping weight and cost; each die in a polyhedral set needs its own dimensions.

What is the standard dice size?

A 16 mm D6 is a common reference size for tabletop and board-game dice. It balances readability, feel in the hand and cost. A polyhedral set is usually proportioned across different shapes: calling it a 16 mm set does not mean all seven dice have the same dimensions.

Common dice sizes and what they are best for

• 12 mm (mini D6) — compact travel sets, pouches and games that need lots of dice; harder to read for some players.
• 16 mm (common D6) — an everyday choice for RPG and board-game ranges; specify the other shapes separately.
• 19–20 mm — a larger D6 or a common D20, depending on shape and measuring convention; confirm which die the measurement describes.
• 25 mm and up (oversized) — display pieces, collector D20s, giveaways and larger numbers; check readability for the intended player.

How big is a D20?

Yes. In a polyhedral set, the D20 and D6 have separate dimensions even when the set is sold under one nominal size. D20s around 19–20 mm are common, while oversized standalone D20s are often around 25–55 mm for display and collector use. Confirm the measuring convention and review the dimensions of each shape before ordering.

12mm vs 16mm dice

A 12 mm mini D6 is approximately 0.47 inches across a cube edge; a 16 mm D6 is approximately 0.63 inches. The mini format saves space for travel or games using many dice. The 16 mm format is a common tabletop reference and provides more space for readable numbers. Compare the actual dice and specify each shape separately when planning a polyhedral set.

How are dice measured?

For a D6, state the length of a cube edge. For a D20, say whether the dimension is across opposite faces or point to point. Keep that convention consistent when comparing samples, artwork and packaging dimensions.

How does size affect custom dice cost?

Bigger dice use more material and affect finishing, packaging and shipping weight. A 25 mm gemstone D20 requires more stone than a 16 mm one, so confirm the size when requesting a quote. For CuiShen’s custom gemstone dice, specify the material, each die’s dimensions, set composition, quantity, engraving and packaging when you request a gemstone dice quote. MOQ 10 sets; custom production timing is confirmed by material, quantity and workmanship.