Picture Frame Size Calculator – Free Mat, Frame and Print Size Tool

Our free picture frame size calculator works out the mat window, the mat size, the frame size, and the outside size of the frame for any artwork, with an even or a bottom-weighted border. It finds the nearest standard US and metric frame, shows your picture to scale in the frame, and prints a cutting sketch. A second tab turns pixels into print sizes at 150, 240, and 300 dpi. Everything runs in your browser.

How to Use the Picture Frame Size Calculator

The “Frame & mat” tab tells you how big the mat and the frame have to be.

1. Choose your units. Pick inches, cm, or mm at the top. In inches, results are shown in fractions of 1/8 or 1/16 inch, or as decimals.
2. Enter the art size. Type the width and height, or pick a common print size such as 8 × 10 in or A4. You can type fractions like 8 1/2 or 8-1/2 as well as 8.5.
3. Set up the mat. Choose a single mat, a double mat, or no mat. Size it by the border width, or pick a frame size and let the calculator work out the borders. Choose an even border or a wider bottom border.
4. Set the overlap. The mat window is usually a little smaller than the art, so the mat holds it in place. You can also float the art in a window that is larger than the artwork.
5. Describe the frame. Enter the moulding width, the rabbet lip, and the clearance, then pick frame and mat colors for the preview.
6. Read, copy, or print. The results update as you type. “Use this frame” switches to the nearest standard frame, “Copy results” copies all sizes as text, and “Print cutting sketch” opens a page with a dimensioned drawing of the mat.

The preview is drawn to scale. Pick a masterpiece or click “Use your photo” to see your own picture in the frame, and “Height from picture” matches the art height to its proportions.

What the Results Mean

Mat Window and Mat Size

The mat window, also called the opening, is the hole cut into the mat. With an overlap, it is the art size minus twice the overlap. The mat size adds the border on each side. For example, an 8 × 10 in print with a 1/4 in overlap on each side gets a 7 1/2 × 9 1/2 in window, and a 2 in border makes the mat 11 1/2 × 13 1/2 in. The glass and the backing board are cut to the same size as the mat.

Frame Size, Rabbet, and Outer Size

A frame is sold by the size of what goes inside it, not by its outside size. An 11 × 14 in frame holds an 11 × 14 in mat, glass, and backing. The recess on the back of the moulding that holds them is called the rabbet. Framers cut it slightly larger than the mat, usually by about 1/8 in in total, so the package drops in easily. That extra room is the “Clearance” field.

The outer size is the rabbet size plus twice the moulding width minus the rabbet lip, the size you need to plan a gallery wall. The rabbet lip, often around 1/4 in, also covers the outer edge of the mat, so the visible border is a little narrower than the border you cut. The calculator shows both.

United Inches and Moulding Length

Many frame shops price custom frames by united inches: the width plus the height of the frame size, in inches. An 11 × 14 in frame is 25 united inches. The moulding length is the sum of the outer edges of the four mitered pieces. Buy about 10% more to allow for the saw cuts and for trimming the miters.

Nearest Standard Frame

The calculator looks for the smallest ready-made frame that holds your mat. It checks US sizes from 4 × 6 to 32 × 40 in and metric sizes from 13 × 18 to 70 × 100 cm, plus the A sizes A4 to A0. For each one, it tells you which borders a mat needs to fill that frame. “Use this frame” switches to that frame and recalculates the borders.

Mat Options Explained

• Bottom weighting: a bottom border that is slightly wider than the top and sides. Framers often add about 1/4 to 1/2 in at the bottom, and the “Bottom extra” field sets the exact amount.
• Overlap: an overlap of 1/8 to 1/4 in per side keeps the print from slipping through the window. Ready-cut 11 × 14 in mats for 8 × 10 in prints usually have a 7 1/2 × 9 1/2 in window, which is 1/4 in per side. If you need to see the whole image, use a smaller overlap or a slightly larger print.
• Float: the window is larger than the art, and a gap shows around the edges of the paper. This suits deckled edges and signed margins.
• Double mat: a second mat under the first one shows as a thin line around the art. The “Bottom mat reveal” sets how much of it shows on each side, and the calculator gives both window sizes. The border width is measured from the top mat window.
• No mat: the art goes straight into the frame, and the rabbet lip covers its edges. The calculator shows how much of the picture stays visible.

Print Size and DPI

The “Print size & DPI” tab tells you how large you can print a digital image. Enter the width and height in pixels, or click “Load image file” to read them from a photo or a scan. Your file stays on your device.

The table shows the largest print at 150, 240, and 300 dpi and at a resolution of your choice. The formula is simple: pixels divided by dpi gives inches. An image 6,000 pixels wide prints 20 in wide at 300 dpi and 40 in wide at 150 dpi.

Below, enter a print size or pick a standard one. The quality light rates the resulting resolution: 300 dpi and more is excellent, 200 to 299 is good, 150 to 199 is fair, and anything under 150 is low. It also shows the pixels needed for that size and how much the image must be cropped to fill it. A 3:2 camera image on an 8 × 10 in print, for example, loses 16.7% of its long side. The crop preview shows which part of your picture is kept, and “Frame this print” carries the print size over to the frame tab.

The list of standard print sizes rates every common US or metric size for your image at once.

DPI or PPI?

Strictly, PPI (pixels per inch) describes how densely an image’s pixels are placed on paper, and DPI (dots per inch) describes how many ink dots a printer lays down. In everyday use, and in most print shop upload tools, “300 dpi” means 300 image pixels per inch, and that is how the calculator uses the term.

How the Calculator Works

All sizes are calculated in millimeters and converted for display, so switching units adds no rounding errors. Inch results are rounded to the nearest 1/8 or 1/16 in, also in the copied text. The preview is drawn to scale on a canvas, and your picture is scaled to cover the art area, just as a print that is larger than the window would be.

When you load a file, the calculator reads its pixel size from the decoded image. It does not read a dpi value stored in the file, because that value does not change how many pixels you have.

Tips for Framing Art

• Check standard sizes first. A mat cut to fit a ready-made frame usually costs far less than a custom frame.
• Use acid-free mat board for anything you want to keep. Our guide to the giclée print explains what makes a reproduction last.
• Plan the print with the frame in mind. Paintings often come in standard canvas sizes, and art prints in standard paper sizes. Matching these saves cutting.

Who Uses a Frame and Mat Calculator?

• Artists plan frames for exhibitions and work out print sizes for editions. If you sell reproductions, our guide on how to make and sell prints of your art covers the whole process.
• Photographers check how large a file can be printed and how much a standard frame crops it. The photography basics guide explains how resolution relates to your camera.
• DIY framers print the cutting sketch, and collectors plan gallery walls with the real outside sizes.

To plan the composition of a picture before it goes into the frame, try our golden ratio overlay.

Your Images Stay Private

The calculator runs entirely in your browser. Photos you load to preview or to read their pixel size are never uploaded. There is no sign-up and no limit. Only the sample paintings, such as Girl with a Pearl Earring and The Starry Night, are loaded from Wikimedia Commons.

More Free Art Tools

All our tools are free, run in your browser, and need no account. See them all on the free art tools page.

• Photo to sketch: turn a photo into a pencil sketch or line art.
• Photo to coloring page: turn any picture into a printable coloring page.
• Image to pixel art: convert an image into editable pixel art.
• Notan generator: plan light and dark shapes with a two- or three-value study.
• Art grid tool: put a drawing grid over any photo.
• Golden ratio overlay: check your composition with a golden spiral and rule of thirds.
• Perspective grid generator: print one-, two-, and three-point perspective grids.
• Paint by number generator: turn a photo into a printable paint by number template.
• Image color picker: find the exact colors in any photo or painting.
• Color name finder: get the name of any HEX, RGB, or photo color.
• Color wheel: find complementary, triadic, and analogous colors.
• Color mixer: mix paint or screen colors and find paint recipes.
• Color palette generator: create matching color schemes or a palette from an image.
• Color blindness simulator: see images and palettes as color blind people do.
• Art pricing calculator: find a fair price for your paintings and prints.
• Art prompt generator: get random ideas for drawing and painting.
• Random character generator: create an original character with traits and a palette.

Frequently Asked Questions

How Do I Calculate the Frame Size for a Picture With a Mat?

Subtract twice the overlap from the picture size to get the mat window, then add twice the border width. An 8 × 10 in print with a 1/4 in overlap and a 2 in border needs an 11 1/2 × 13 1/2 in mat, and that is also the frame size you need. The calculator above does this for any size and unit.

What Size Frame Do I Need for an 8 × 10 Picture With a Mat?

The most common choice is an 11 × 14 in frame. With a 7 1/2 × 9 1/2 in window, the mat borders are 1 3/4 in at the sides and 2 1/4 in at the top and bottom. For wider borders, a 12 × 16 in or 16 × 20 in frame works too.

How Much Should a Mat Overlap the Picture?

Usually 1/8 to 1/4 in on each side. Ready-cut mats often overlap 1/4 in per side. If the edges of the picture must stay visible, float it in a larger window instead.

Does the Frame Size Include the Frame Itself?

No. A frame’s size is the size of the mat, glass, or picture it holds. The outside of the frame is larger by twice the visible moulding width, and the calculator shows that outer size separately.

What Is a Bottom-Weighted Mat?

It is a mat with a bottom border that is wider than the top and sides, often by 1/4 to 1/2 in. It keeps the picture from looking as if it is sinking in the frame. Choose “Bottom border: Wider” in the calculator and enter the extra amount.

How Big Can I Print a Photo at 300 DPI?

Divide the pixels by 300. A 6,000 × 4,000 pixel photo prints at 20 × 13.33 in at 300 dpi, and at 25 × 16.67 in at 240 dpi.

What Resolution Do I Need for an 8 × 10 Print?

At 300 dpi, an 8 × 10 in print needs 2,400 × 3,000 pixels. At 240 dpi, 1,920 × 2,400 pixels are enough. The second tab shows this for any size.