Free framing calculators
Picture framing & matting calculators that get every size right.
Mat borders, collage mats, frame and glass sizes — to the 1/16″ or the millimeter, with a live preview of the finished piece.
No sign-up · inches & cm · results in seconds
Start here — what are you framing?
Pick what you're framing and we'll send you to the right calculator.
Comparing ISO A-sizes to US frame sizes? See international frame sizes →
All framing calculators
Learn the craft
The calculators do the arithmetic; the guides explain the choices behind it. Start with how to measure for a mat to turn an artwork into an exact opening, then read how wide a mat border should be to scale the border to your piece and frame. Framing needlework instead? The cross-stitch framing walkthrough covers washing, lacing over board, and the fabric margin you need.
Not sure what to order off the shelf? Browse the standard frame sizes and standard mat sizes charts to match your print to a stock size before you reach for a calculator. The frame chart lists the common US sizes with their cm equivalents, aspect ratios, and what each one is typically used for; the mat chart pairs every pre-cut mat with its outer size, window opening, and the print it fits. Reach for the frame chart when you’re buying a ready-made frame, and the mat chart when you want a pre-cut mat rather than cutting your own — then a calculator fills in the exact borders.
Framing & matting guides
Short, practical guides to the decisions the calculators do the math for.
Who FramingMath is for
FramingMath is a free picture framing calculator and matting calculator suite that turns a few measurements into the exact numbers you need at the cutting mat and the checkout. Enter your artwork size and it works out mat borders, the window (opening) to cut, the outside mat and frame size to order, and the glass, acrylic and backing to cut — in inches to the 1/16″ or in centimeters to the millimeter, with a live preview of the finished piece.
It is built for anyone who frames their own work. Interior decorators and stylists size galleries and multi-opening collage mats; artists and printmakers mat editions to standard frames; photographers fit prints to off-the-shelf sizes; and crafters — cross-stitch and needlework finishers, and diamond-painting framers — get a clean, even border around an odd-sized piece. Hobby framers and small frame shops use it to double-check a cut before committing a sheet of board.
Every calculation runs in your browser. There is no sign-up, no app to install, and nothing to pay — just pick a calculator above and start measuring.
Picture framing & matting calculator FAQ
What can a picture framing calculator work out?
Our picture framing calculators turn your artwork size into the numbers you actually cut and buy: the mat border and window (opening) size, the outside mat and frame size to order, the glass, acrylic and backing cut sizes, and even-spaced openings for a multi-opening collage mat. Every result shows in inches to the 1/16 inch or in centimeters to the millimeter.
Which calculator should I use for matting?
For a single picture, start with the mat border calculator (enter the artwork and the border width) or the mat opening calculator (find the exact window to cut). For several photos in one mat, use the multi-opening mat calculator, which spaces the windows evenly and gives a per-opening cut list.
Do the calculators work in inches and centimeters?
Yes. Every tool accepts inches with fractions down to 1/16 inch and centimeters to the nearest millimeter, and shows the results in both. They are completely free, need no sign-up, and run entirely in your browser.
What is framing math, and can you show an example?
Framing math is the handful of calculations that turn an artwork size into the sizes you cut and order — the mat opening (window), the mat border, the outside frame size, and the glass and backing. Here is a worked example: for an 8×10 photo with a 2-inch mat border, the opening is cut at 7½ × 9½ inches (a ¼ inch smaller on each edge so the mat holds the print), and the outside mat and frame size is 11½ × 13½ inches — the opening plus 2 inches of border on every side. The glass and backing drop in about 1/16 inch smaller all round. Every calculator here runs this framing math for you and shows the numbers, so you can follow the example with your own sizes.
What framing math formulas do the calculators use?
They use a few simple formulas. The mat opening is the artwork minus twice the overlap (¼ inch per side by default), so the window sits just inside the print. The outside mat and frame size is that opening plus the border on each side. The glass, acrylic and backing are cut from the frame inside (rabbet) size minus about 1/16 inch per side so they drop in cleanly. For a collage layout, the multi-opening calculator takes the space left after the margins and gutters and divides it equally between the windows. Each tool shows its formula alongside the result, so nothing is a black box.