Dartboard Dimensions and Measurements | Oche

A dartboard looks simple, but every ring, bed and bull is cut to a precise measurement. Knowing the dimensions explains why the game plays the way it does — why trebles are so punishing, why the bull is harder than it looks, and why the numbers sit in their famously awkward order.

The headline measurements

Taken from the WDF equipment specifications and matched by the PDC and the DRA:

• Overall board diameter: 451 mm
• Scoring area diameter: 340 mm (outer double to outer double)
• Double & treble ring width: 8 mm (inside the wires)
• Inner bull (50): 12.7 mm diameter
• Outer bull (25): 31.8 mm diameter
• Bull to treble wire (centre): 107 mm
• Bull to double wire (centre): 170 mm

Our dimensions guide lays out the full table with the ring spacing.

Why the trebles feel so small

That 8 mm ring width is the headline figure for anyone chasing 180s. A treble 20 bed is just 8 mm deep and a few millimetres wide — barely the thickness of the dart barrel itself. It’s why hitting three trebles in a visit is a genuine skill and why the nine-dart finish is so rare.

The bull is smaller than you think

The inner bull is only 12.7 mm across — half the size of the outer bull ring at 31.8 mm. On a board hung at the regulation 1.73 m height, that tiny circle is a real target, which is why “on the bull” deciders are genuine pressure throws.

The number order

The layout is deliberate, not random. From the top going clockwise:

20, 1, 18, 4, 13, 6, 10, 15, 2, 17, 3, 19, 7, 16, 8, 11, 14, 9, 12, 5

High-scoring beds are flanked by low ones — the 20 sits between 1 and 5, the 19 between 7 and 3. Miss the treble 20 and you’re punished with a single 1 or 5, which rewards accuracy over aiming at a cluster of big numbers.

Knowing the board, scoring the board

Once you know where every bed sits, the next step is tracking how often you hit the ones that matter. The Oche X01 scorer records your treble and double-hit rates over time, so the 8 mm targets you’re aiming at turn into hard numbers you can actually improve.