What angle should you sharpen a knife to?

Ask ten people who sharpen knives what angle to use and you’ll get answers from 12° to 25°, most of them defensible for some knife. The makers are more specific — many publish a factory figure on their own care pages — and the practical advice buried in all of them is the same: put back the edge the factory ground.

The catch is that the industry states angles two different ways and often doesn’t say which one it’s using. A “20-degree edge” is either a hard-use working bevel or something approaching a razor, depending on a word the care page may have left out.

Why is “match the factory edge” the standard advice?

Because the factory angle is the one the blade’s steel, thickness and grind were chosen around, and re-establishing it removes less metal than changing it. CRKT’s sharpening guide puts it plainly: each knife comes with a factory-set edge angle, and sharpening is the act of restoring it. Benchmade opens the angle advice in its care guide with the same instruction: “Match the factory edge angle.”

There’s a mechanical reason. Sharpening at the existing angle touches only the last fraction of a millimeter of steel — a few light passes and the apex is back. Cutting a new angle means regrinding the whole bevel until the two planes meet again, which takes real time on a stone and real metal off the blade. Do that casually a few times and you’ve shortened the knife’s life for nothing.

What’s the difference between per-side and inclusive angles?

A per-side angle measures one bevel against the centerline of the blade; an inclusive angle adds both bevels together — so the same number can describe two radically different edges. Work Sharp’s edge-angle explainer is one of the few maker pages that defines the terms outright: “Edge angle can be measured per side … or inclusive, measuring the angle that the tip itself forms in its entirety to both sides” — adding that “we usually talk about angles per side, as that is more relevant to sharpening.” Per side is the angle your hand actually holds against the stone.

Run the arithmetic once and the stakes are obvious. Sharpened at 20° per side, a knife carries a 40° inclusive edge — the durable end of pocket-knife territory. Sharpened at 20° inclusive, it carries 10° per side — thinner than a Scandinavian bushcraft bevel. Same number, two edges with nothing in common.

Spyderco shows what clear labeling looks like. The Tri-Angle Sharpmaker’s keyed base sets its stones at “30° (15° each side) or 40° (20° each side)” — both conventions, same line, no ambiguity.

Benchmade shows how slippery the conversion is even when a maker does label. Its care page states 30–35° inclusive, glossed as “about 17–20° per side” — but 17–20° per side doubles to 34–40° inclusive, and 30–35° inclusive halves to 15–17.5° per side. The two halves of the maker’s own sentence don’t quite reconcile. That’s not a scandal; it’s a demonstration. If the conversion can wobble on a manufacturer’s care page, it’s worth pinning down before you grind.

What angles do knife makers actually publish?

Normalized to per side, the published figures cluster between roughly 15° and 22.5° — but several makers give a number with no convention attached at all. Here’s what the care pages actually say:

Maker	Published figure	Per side or inclusive?	Source
Benchmade	30–35° inclusive (“about 17–20° per side”); kitchen cutlery typically 14° per side	Both stated — the halves don’t quite match	Knife Care 101
Spyderco	Sharpmaker settings of 30° or 40°	Both stated: “15° each side” / “20° each side”	Sharpmaker page
Morakniv	Scandi grind 23° (blades up to 2.5 mm) or 27° (thicker); micro bevel 35–45°	Inclusive — labeled “total edge angle”	Grinds and edge angles
Kershaw	“Original sharpened angle of 18°–22°”	Not stated	Product care
Gerber	20–30° recommended for any Gerber knife	Not stated	Sharpening guide
Opinel	“Approximately 20°” between blade and sharpening rod	Not stated	Sharpening tips
CRKT	No factory figure published; recommends 17–25° for EDC knives	Per side — for the recommendation; the factory edge goes unstated	Sharpening mechanics
Buck Knives	22.5° “works well”	Not labeled — described as the angle held against the stone	Buck’s sharpening guide

Where the third column says “not stated,” the page describes holding the blade against a stone or rod at that angle — a per-side measurement in practice — but the page leaves you to draw that inference.

Context usually rescues the unlabeled numbers. Read Kershaw’s 18–22° or Gerber’s 20–30° as inclusive and you’d get 9–15° per side, angles no production folder ships at, so per side is the only sensible reading. But “the only sensible reading” is you doing the maker’s labeling for them, and guessing in the other direction is exactly how edges get wrecked.

Morakniv is the clean counter-example, and the knife where guessing would hurt most. Its knowledge page states a “total edge angle” of 23° for Scandi blades up to 2.5 mm thick and 27° for thicker ones — numbers that would pass as plausible per-side angles and are actually half that, 11.5° and 13.5° a side. The optional micro bevel is listed at 35–45° total. Put a familiar-sounding 20° per side on a Scandi grind and you haven’t sharpened the knife; you’ve doubled its edge angle.

How do you hold an angle without a jig?

Halve your way there: hold the blade square to the stone at 90°, tilt to about 45°, then halve again and you’re near 22.5° — the angle Buck’s sharpening guide says “works well.” It’s the rare trick that needs no gear and lands within a few degrees of most factory edges. From there, ink the bevel with a marker and make three light passes: ink gone at the shoulder means you’re too shallow, ink gone only at the very edge means you’re close.

Guided tools remove the guessing. Work Sharp’s Guided Field Sharpener lists its spec as “Edge Angles: 20°, 25°” — and note that even a sharpening company’s spec line skips the per-side label; it’s their education page that establishes the company talks in per-side terms. Spyderco’s Sharpmaker inverts the problem entirely: the base holds the stones at the angle, and you keep the blade vertical, which is the easiest thing in sharpening to do repeatably.

When should you move off the factory angle?

When the edge keeps failing the same way — chipping or rolling wants a wider angle, and a knife that only ever slices soft material can afford a thinner one. The published ranges agree closely. Work Sharp puts kitchen knives at 15–18°, pocket knives at 17–25° and outdoor blades at 25–35° per side; CRKT’s guide overlaps it almost exactly, recommending 17–25° per side for everyday carry, 15–20° for slicing-focused work and 20–30° where durability matters. The only real daylight between the two is at the heavy end — 35° versus 30° for hard outdoor use — worth knowing if you’re sharpening a chopper, immaterial for a pocket knife.

The trade is stated flatly in Work Sharp’s explainer: “as an angle gets wider the edge grows stronger,” while “thinner angles like 15 degrees, are fragile and the edge will roll to one side or the other with heavy use.” Steel sets the limits of that trade — a hard, fine-grained steel holds a thin bevel that would roll immediately in a softer one. If the steel name stamped on your blade means nothing to you, our guide to knife steel names is the place to start.

Can every blade be resharpened?

No — Silky saws are the standing exception worth knowing about. Silky’s US distributor states that the impulse-hardened teeth on most of its blades “cannot be sharpened and are recognizable by the black teeth tips”; the hardening buys “a lifespan of three times that of non-treated teeth,” and when it’s spent, the answer is a replacement blade, not a file. The same page notes that blades without hardened teeth can be sharpened with a file. If you’ve been eyeing a folding saw with a whetstone in hand — don’t.

Serrated knife edges are the other special case: sharpenable, but scallop by scallop with a rod or a rounded stone corner, the way Spyderco’s Sharpmaker instructions present the rounded edge of the stone to serrated blades. Whether you want serrations in the first place is its own decision — our serrated vs plain edge guide walks through it.

The short version

Sharpen at the angle the factory ground, and only move off it when the edge keeps failing in a way a different angle would fix. Before trusting any published number, find out whether it’s per side or inclusive — the difference is a factor of two, and several makers, Kershaw and Gerber among them, publish figures without saying which they mean. Benchmade, Spyderco and Morakniv label theirs, and normalized to per side, nearly everything with a pocket clip lands between 15° and 20°. Scandi grinds run far thinner and are stated in total degrees, and impulse-hardened saw teeth don’t get sharpened at all. When in doubt, hold something close to 20° a side — the middle of nearly every range any maker publishes.