How to use a mitre box: perfect mitre cuts in simple steps

Take the stress out of using a mitre box and saw for your DIY projects

panelled wall and skirting board with DIY mitre box on floor

How to use a mitre box is a question frequently pondered by DIYers tackling a DIY project with mitre joints. In this guide, we’ll explore how to use a mitre box and hand saw, focusing on making 45-degree cuts and other common mitre angles. With a saw blade and a mitre box—you’ll learn to create clean cuts using saw guides and degree slots. We’ll cover essential techniques, from securing your workpiece with a hold-down clamp or screw to using a tape measure for precise measurements and executing the perfect push stroke. Whether you’re handling long pieces of wood or smaller pieces of wood, I’ll share tips for making standard miter cuts, then we’re going to look at a fun DIY project that you can complete with a mitre box: making DIY picture frames.

What is a Mitre box?

Black plastic mitre box - side view — Plastic mitre box

Mitre boxes are essentially saw guides for using with hand saws. Mitre boxes have pre-cut guide slots at various angles, enabling you to make accurate cuts for DIY projects like picture frames and crown moulding. Mitre boxes are available in various materials and sophistication levels, from inexpensive plastic models to robust metal ones with self-clamping features and detachable saw blades and for tall pieces of wood like skirting you might want to use my DIY tutorial on how to create a DIY mitre box from wood offcuts.

Embarking on a new project that involves making precise angled cuts, like crafting a picture frame or installing trim, can be both exciting and daunting. While power saws and various types of mitre saws offer convenience, mitre boxes remain the best option for achieving accurate cuts without breaking the bank.

How to use a mitre box

Mitre boxes are super simple to use.

To use a mitre box, first, secure it to your work surface using screw holes or a lip on one side to clamp it in a vice for stability.
Once the base is stable, align your piece of wood with the guide slot corresponding to the desired angle—common angles include 22.5, 45, and 90 degrees.
Use a hard-backed tenon saw, ideal for its rigidity, and saw along the cut line with short strokes to achieve a clean, precise cut.

Mitre boxes come in various forms, such as the Stanley mitre box set, and are suitable for different materials and tasks, from cutting PVC pipe to trim work. For best results, make test cuts on a piece of scrap lumber to ensure the correct angle.

Whether you’re making miter joints or standard mitre cuts, using a mitre box is the best way to achieve accurate cuts without the need for more advanced power tools like electric miter saws or table saws.

A piece of wood moulding lined up in a black plastic mitre box

Beware, plastic can be soft and easy to saw through, so you might want to make a mitre box using offcuts of wood. Read how to here.

A piece of skirting board clamped in a mitre box about to be sawn

Now you know how to use a mitre box, it’s time to flex your woodworking skills and tackle a DIY project with mitre joints; here is a fun example.

How to use a mitre box to make DIY picture frames

Picture frames are super simple to make and can be as detailed or simple as you like.

Measure the item you wish to frame (including the mount) to determine the length and height required.
Measure and mark your piece of wood or moulding with the frame dimensions, remembering that the corners will have angled cuts, so your length and height will go to the bottom of the 45-degree angle.
Cut the four sides and line them up to check they fit.
Gently sand the edges to smooth them off.
Glue the pieces together and clamp in place while the adhesive sets.
Cut out some strong cardboard for the back mount.
Staple or brad nail the sides and bottom of the cardboard onto the back of the frame creating an envelope to slide your chosen art into.

Thanks so much for reading about how to use a mitre box to make DIY picture frames. I’d love to keep you up to date with future DIY, decorating, interior styling and upcycling projects, if you would like to receive my (not more than weekly & no spamming I promise) emails then please subscribe by scrolling down to the box at the bottom of the page. Don’t forget to check out my other blog posts a few examples are linked below…