How Often Should You Flatten a Whetstone?

Flatten a whetstone when wear has made the sharpening surface meaningfully uneven. There is no universal number of knives or sharpening sessions.

Why do stones become dished?

Repeated abrasion removes stone material, especially from the areas you use most.

How can you check flatness?

Use a straightedge, pencil grid or another reliable reference across the stone surface.

When should you flatten?

Flatten when a hollow or ridge begins to interfere with stable contact between the bevel and stone.

Do soft stones need it more often?

Generally, stones that release abrasive more quickly can wear faster, but technique and pressure also matter.

Should you flatten after every use?

Not automatically. Some users prefer frequent light flattening because it is quick; others wait until visible wear develops.

Why does flatness matter?

A flat reference surface makes it easier to preserve consistent bevel geometry, especially on wide bevels and single-bevel knives.

See How to Flatten a Whetstone.