What Angle Should You Sharpen a Japanese Kitchen Knife?

Use the angle or sharpening method recommended for your specific knife, not a universal “15 degrees for Japanese knives” rule. For example, Shun documents 16° per side for many of its double-bevel knives. That is a Shun product specification, not a standard for every Japanese knife. If the original bevel is uncertain, identify the model or ask the maker before removing metal.

Does 15 degrees mean per side or total?

Sharpening specifications usually describe an angle on one side of the blade. For a symmetric double-bevel knife, a 15° angle on each side gives a nominal 30° included edge angle. Do not confuse the two measurements: changing a 15°-per-side edge to 15° total changes its geometry substantially.

This calculation assumes equal bevel angles measured from the blade centerline. Real blades may have asymmetric bevels, convex sections or microbevels, so the visible edge can be more complicated.

Why do different Japanese knives have different angles?

Edge geometry reflects the maker's design, steel and heat treatment, blade thickness and expected tasks. A thin precision cutting edge and a knife made for rougher tasks may require different maintenance. An advertised steel name or Rockwell hardness value does not by itself establish the correct sharpening angle.

Shun's official FAQ specifies 16° per side for its knives and describes a matching honing guide. Its series comparison also distinguishes the single-bevel Yanagiba from most double-bevel designs. Treat those figures and distinctions as product-specific information.

How can you find the angle on your own knife?

1. Look up the exact model and manufacturer's maintenance or sharpening instructions; check whether a figure is stated per side.
2. Confirm the knife is double bevel and whether the maker specifies asymmetric geometry. See single vs double bevel.
3. Look for an existing bevel instead of immediately grinding a new one. If damage or previous sharpening obscures it, ask a qualified sharpener.
4. Choose a stable stone and prioritize repeatable technique over chasing an exact angle without appropriate tools.

Should you change your knife to a more acute angle?

Not solely to chase perceived sharpness. Reprofiling removes metal, and an edge that is too thin for its intended use may be more vulnerable to damage. The outcome depends on more than angle alone. If you want to change geometry, consult the manufacturer or an experienced sharpener, particularly for thin or expensive blades.

What about single-bevel Japanese knives?

Do not use the simple “same angle on both sides” calculation for a traditional Yanagiba, Deba or Usuba. Its front bevel and back face require different handling. Applying the ordinary double-bevel process to both faces can damage the intended geometry. Follow the knife maker's sharpening guidance or use a specialist familiar with the knife.

How do you hold a consistent angle on a whetstone?

Begin with a secure stone, modest pressure and the manufacturer's specified bevel. Keep the blade's contact consistent while moving across the stone; use suitable guidance or supervised practice if you cannot maintain the angle. Never slide a finger along the edge to test sharpness. For the full double-bevel process, see our whetstone sharpening walkthrough.

If you are not sure whether the edge needs material removed, first compare honing and sharpening.

If the edge is chipped, cracked or damaged, consult the problem-solving checklist rather than attempting a routine angle adjustment. Our knife selection helper covers the earlier choice of knife shape.

Evidence and scope

The 16° example comes from Shun's published product guidance; the other table entries illustrate angle arithmetic and do not represent manufacturer specifications or product recommendations. This article does not report personally measured angles, sharpening trials, edge-retention tests or a ranked comparison.