An original painting on canvas at the VanArtHub gallery on Davie Street in Vancouver.

Free tool · No sign-up

Canvas stretching calculator

Enter the size of your painting and get the bar lengths, the depth it needs, whether it needs a cross-brace, and how much unpainted margin the canvas must have. Everything is worked out in your browser and nothing is sent anywhere.

Measure the painted image only. The calculator adds the wrap and the margin it needs.

Where these numbers come from

Bar depth follows the longest side, because a long bar bows inward under the pull of the fabric and a bowed bar slackens the canvas at the middle of that side. The four bands the calculator uses are the same ones set out in stretcher bars explained.

The margin figure is the unpainted border the canvas needs so the fabric can wrap the bars and take staples. Four to five centimetres a side is comfortable. Under about two and a half becomes difficult, and a canvas trimmed right to the image cannot be stretched conventionally at all. See how a canvas is stretched.

The perimeter is shown because that, not the area, is what stretching is priced from. Bars are bought and cut by the length. See what changes the cost of stretching.

Common questions

How does the calculator decide the bar depth?

By the longest side, because that is what bows. Up to 60 cm a shallow bar is fine, 60 to 100 cm wants a medium depth, 100 to 150 cm wants a deep bar and one cross-brace, and past 150 cm it needs bracing both ways. The same four bands are set out in stretcher bars explained.

Why does it ask for the image size and not the canvas size?

Because the image is the part you know and the canvas is the part it works out. The unpainted margin has to wrap the bars and take staples, so the calculator adds the bar depth plus a working border on every side and tells you the total piece of fabric you need.

Why does it show the perimeter?

Because that is what stretching is priced from. Bars are bought and cut by the length, so cost follows the distance around the outside rather than the area. A long thin canvas can cost more than a squarer one covering more wall.

Does it give me a price?

No, and deliberately. Cost depends on the perimeter, the bar depth, the bracing and the condition the canvas arrives in, and no form can ask about condition honestly. It shows you the perimeter so the number that drives the quote is visible, and stops there.

What is different about a gallery wrap?

The image continues round the sides, so the painted area has to extend beyond the front face by at least the depth of the bar, on top of the unpainted margin. Select gallery wrap and the calculator says how much extra painted area you need. Tell the artist before they paint it if you can.

Is anything I enter sent to you?

No. Every calculation runs in your browser and nothing is submitted anywhere. There is no form endpoint on this page.

Want us to do it?

Bring the piece to 1242 Davie Street in Vancouver, rolled or loose, and we will check the margins with you and quote the actual canvas.

Canvas and art stretching