The Complete Router‑Bit Size Chart Every Woodworker Needs (Free PDF)

If you’ve ever stared at a drawer of bits and wondered whether that 1/4‑inch spiral will actually fit your 3/4‑inch groove, you’re not alone. I’ve spent more evenings than I care to admit measuring, swapping, and sometimes cursing my own tools. That’s why I finally put together a single, easy‑to‑read chart that shows every common router‑bit size and the best uses for each. It’s free, it’s printable, and it lives right here on Router Bits Review.

Why a Size Chart Matters Right Now

Woodworking projects have a way of getting more ambitious as the seasons change. Spring brings porch decks, summer invites garden benches, and fall? That’s when the “I’m finally going to make a live‑edge coffee table” vibe hits hard. All those projects need the right bit, and the wrong size can waste material, ruin a joint, or even damage your router. A quick glance at a reliable chart saves you from those headaches before you even turn the machine on.

What the Chart Covers

H2 Standard Shank Diameters

Most routers use a 1/4‑inch or 1/2‑inch shank. The chart lists both, so you can see at a glance which bits will fit your collet without a conversion calculator.

• 1/4‑inch shank – Great for light‑duty work, smaller routers, and tight spaces.
• 1/2‑inch shank – Sturdier, less vibration, ideal for heavy cuts and larger bits.

H2 Cutting Diameter Ranges

The cutting diameter is the actual width of the cut the bit makes. I’ve grouped them into three practical buckets:

1. Mini (under 1/4‑inch) – Perfect for delicate edge profiling, small dovetails, and in‑lay work.
2. Mid‑size (1/4‑inch to 1/2‑inch) – Your go‑to for most rabbets, round‑overs, and standard mortises.
3. Large (over 1/2‑inch) – Used for big grooves, wide flush trims, and heavy‑duty joinery.

Each entry in the chart shows the exact diameter, the recommended shank size, and a quick note on typical applications.

H2 Profile Types

Router bits come in many shapes, and the chart tags each diameter with its profile:

• Straight – Simple plunge cuts, dados, and mortises.
• Round‑over – Soft edges for furniture.
• Chamfer – Angled edges, often 45°.
• V‑groove – Decorative lines and lettering.
• Flush‑trim – Matching a template or edge.
• Spiral up/down – Clean cuts in both hardwood and softwood.

Knowing the profile helps you pick the right size faster than scrolling through endless product pages.

How to Use the PDF

1. Download – Click the “Free PDF” button on the post page. The file is under 200 KB, so it loads instantly even on a slow connection.
2. Print – I recommend printing on standard letter paper and folding it in half. The layout is portrait‑oriented, making it easy to keep on a bench or in a tool chest.
3. Mark – Use a dry‑erase marker to circle the bits you own. That way you can see at a glance which sizes you still need to buy.
4. Reference – Keep the sheet on your workbench. When a new project pops up, a quick glance tells you whether you have the right bit or need to order one.

Tips for Choosing the Right Size

H3 Measure Twice, Cut Once—Even With Bits

Before you grab a bit, measure the groove or profile you need. A common mistake is assuming a “1/2‑inch round‑over” will give you a 1/2‑inch radius. In reality, the radius is half the cutting diameter, so a 1/2‑inch bit produces a 1/4‑inch radius. The chart includes a column that converts diameter to radius for quick reference.

H3 Match the Shank to Your Router

If you have a compact router with a 1/4‑inch collet, don’t force a 1/2‑inch shank into it. Not only will it damage the collet, it will also cause chatter—vibration that leaves a rough surface. The chart’s shank column eliminates that guesswork.

H3 Think About Material

Hard maple and walnut love a clean, smooth cut. For those, I lean toward spiral up‑cut bits because they pull chips away from the cut, reducing heat. Softer pine can tolerate straight bits, which are cheaper and easier to replace. The chart flags each size with a “hard/soft” recommendation.

Maintaining Your Bits

A size chart is useless if the bits are dull. Here’s my quick maintenance routine:

• Clean after each use – Wipe away resin and dust. A soft brush works fine.
• Inspect the cutting edge – Look for nicks. Even a tiny nick can cause tear‑out.
• Sharpen or replace – I keep a small sharpening stone for minor edge work, but most of the time I replace the bit. The chart helps you know exactly which replacement you need.

Where to Find the Bits

I’m not here to push a single brand, but I’ll share where I usually source my bits:

• Local woodworking stores – Great for trying a bit before you buy.
• Online specialty shops – Offer bulk packs that match the chart’s most common sizes.
• Manufacturer’s direct sites – Often have the newest profiles before they hit the shelves.

When you order, cross‑check the product listing with the chart. If the description says “1/2‑inch shank, 1‑inch cutting diameter,” you’ll know exactly where it fits in your toolbox.

A Little Story From My Shop

Last summer I was building a set of nesting tables for a client who wanted a subtle “soft‑edge” look. I grabbed what I thought was a 3/8‑inch round‑over bit, set the router, and cut the first leg. The edge came out looking more like a sharp bevel than a gentle curve. I pulled the bit, checked the chart, and realized I’d grabbed a 3/8‑inch straight bit with a chamfer profile—same diameter, wrong shape. A quick glance at the PDF showed the correct 3/8‑inch round‑over with a 1/4‑inch radius. One more pass and the tables looked exactly as the client wanted. That moment reminded me why a clear size chart is worth its weight in oak.

Download the Chart Now

Ready to stop guessing and start cutting with confidence? Head over to Router Bits Review, hit the download button, and print your copy. Keep it on the bench, and let it become as familiar as your favorite hand plane. With the right size at your fingertips, every joint, edge, and decorative groove will come out clean, fast, and—most importantly—right the first time.