To match Go stones to a board, compare stone diameter with the spacing between adjacent intersections in both directions. The board’s outside dimensions and a stone’s thickness label cannot establish that fit by themselves.
Measure the relationship that matters
Stones sit on intersections, so neighboring stones share the distance between adjacent grid lines. Boards can have different spacing along their two axes. For a simple illustrative calculation, twenty-millimeter stones on a twenty-two-millimeter spacing leave two millimeters between their nominal edges. That arithmetic does not account for rounding, variation, or handling comfort.
| Measurement | Why it matters |
|---|---|
| Stone diameter | Determines the nominal footprint of a placed stone. |
| Stone thickness | Changes the profile and handling; it is not the diameter. |
| Grid spacing in both directions | Determines separation between neighboring intersections. |
| Board edge margin | Affects how edge stones sit on the board. |
| Bowl capacity | Must accommodate the actual inventory and stone thickness. |
A manufacturer conflict worth resolving
Yellow Mountain Imports lists its US-SF002-A double-convex stones at 7.5 × 21 mm on the standalone stone page. A Shin Kaya kit containing that model code lists the stones at 7.5 × 22 mm and grid spacing at 22 × 23.5 mm. We cannot resolve the diameter difference from those pages. Ask for confirmation of the exact supplied stones before relying on a precise fit calculation.
Do not treat a size number as universal
A label such as size 28 can describe a stone category without supplying every physical measurement needed for compatibility. Record diameter and thickness explicitly. If a seller gives only an overall shipping-box size, request component measurements instead of estimating from a photograph.
Compare loose and bundled components differently
A manufacturer-assembled kit identifies an intended combination, but its specifications can still contain errors or change over time. Separate purchases require an explicit check of the two products. In either case, a nominal zero gap is a reason to verify the actual pieces and grid, not an automatic proof that the set is unusable.
Inspect storage and handling
Thicker stones can require different bowl capacity even when their diameter is similar. Check lids, the complete stone count, and enough table space to reach both bowls. We have not tested sound, surface friction, or how comfortably different players pick up these stones.
Keep uncertainty in the purchase decision
Choose a set whose maker can provide consistent measurements when exact fit matters. Preserve the model codes and confirmed dimensions so replacement stones can be checked later. A broad claim that stones fit every standard board is less useful than the actual dimensions of the components you own.
Sources and method
This is a researched decision guide. Product facts were checked against the primary sources below on November 2, 2026. Selection advice and worked examples are editorial reasoning. This guide does not include hands-on testing.
