Picture Frame Mount Calculator

The mount and frame sizes for a picture, with the traditional weighted bottom edge for a landscape piece.

A mount is cut for the picture rather than the frame, and the two numbers people get wrong are the mount width and the bottom edge. Fifty to one hundred millimetres of mount on each side is the usual range, and a landscape picture traditionally carries 10 to 20 percent more mount at the bottom than at the top, which lifts the image to the optical centre. This calculator returns the cut mount size, the frame size and the visible image area, so the order can go in the first time.

At a glance

What you enter: Artwork length (the long side), Artwork width (the short side), Mount width on each side, Mount style, Extra mount at the bottom, Mount overlap onto the artwork at each edge, Frame moulding face width, Price of mount board per sheet
What you get: Mount size, long side, Mount size, short side, Mount at the bottom, Frame outer size, long side, Frame outer size, short side, Wall area the frame takes, Area of mount board in square metres, Visible image length, Visible image width, Visible image area, Share of the artwork hidden by the mount, How far the weighting lifts the image, Cost of one sheet of mount board
Formula shown: Yes, every step, right below your results.
Cost and privacy: Free, no account needed, and nothing you type is stored.

See worked examples ↓ Read the FAQ ↓ Share this calculator ↓

Artwork length (the long side) mm

The paper or board size, which is usually slightly larger than the printed image.

Artwork width (the short side) mm

Mount width on each side mm

Fifty to one hundred millimetres is the usual range. Leave at zero for no mount.

Mount style

Weighting adds 10 to 20 percent more mount at the bottom and lifts the image to the optical centre.

Extra mount at the bottom %

Ten to twenty percent is the traditional range for a weighted mount. Ignored for an even border.

Mount overlap onto the artwork at each edge mm

Three to six millimetres holds the paper flat without covering the image.

Frame moulding face width mm

The width of the front face of the moulding.

Price of mount board per sheet

Optional. Used for the mount cost.

Reset

Results are estimates for general information only, always verify with a professional or official source before acting on them.

How to use the Picture Frame Mount Calculator

1 Enter Artwork length (the long side) (mm), The paper or board size, which is usually slightly larger than the printed image.
2 Enter Artwork width (the short side) (mm)
3 Enter Mount width on each side (mm), Fifty to one hundred millimetres is the usual range. Leave at zero for no mount.
4 Enter Mount style, Weighting adds 10 to 20 percent more mount at the bottom and lifts the image to the optical centre.
5 Enter Extra mount at the bottom (%), Ten to twenty percent is the traditional range for a weighted mount. Ignored for an even border.
6 Enter Mount overlap onto the artwork at each edge (mm), Three to six millimetres holds the paper flat without covering the image.
7 Enter Frame moulding face width (mm), The width of the front face of the moulding.
8 Enter Price of mount board per sheet, Optional. Used for the mount cost.
9 Press Calculate. You get Mount size, long side, Mount size, short side, Mount at the bottom, Frame outer size, long side, Frame outer size, short side, Wall area the frame takes, Area of mount board in square metres, Visible image length, Visible image width, Visible image area, Share of the artwork hidden by the mount, How far the weighting lifts the image, Cost of one sheet of mount board, and every intermediate step stays visible under "How is this calculated?"
10 Change one number at a time to see what moves the result, that is usually the most useful thing a calculator can tell you.

Worked examples

Real numbers run through this calculator. Open any example to load it into the form above and change it.

A 500 by 400 mm landscape print

A 70 millimetre mount with 18 percent bottom weighting and 22 millimetre moulding.

You enter

Artwork length (the long side): 500 mm
Artwork width (the short side): 400 mm
Mount width on each side: 70 mm
Mount style: 2
Extra mount at the bottom: 18%
Mount overlap onto the artwork at each edge: 4 mm
Frame moulding face width: 22 mm
Price of mount board per sheet: $9.00

You get

Mount size, long side: 640.00 mm
Mount size, short side: 552.60 mm
Mount at the bottom: 82.60 mm
Frame outer size, long side: 684.00 mm
Frame outer size, short side: 596.60 mm
Wall area the frame takes: 0.41 sq m
Area of mount board in square metres: 0.35 sq m
Visible image length: 492.00 mm
Visible image width: 392.00 mm
Visible image area: 192,864.00 sq mm
Share of the artwork hidden by the mount: 3.6%
How far the weighting lifts the image: 6.30 mm
Cost of one sheet of mount board: $9.00

The mount is cut at 640 by 552.6 millimetres with a 70 millimetre border at the top and 82.6 at the bottom, so the frame is ordered at 640 by 553 and sits at 684 by 597 on the wall.

Open this example in the calculator →

A small print with a generous mount

A 250 by 200 millimetre print with a 60 millimetre even mount and a 15 millimetre frame.

You enter

Artwork length (the long side): 250 mm
Artwork width (the short side): 200 mm
Mount width on each side: 60 mm
Mount style: 1
Extra mount at the bottom: 0%
Mount overlap onto the artwork at each edge: 4 mm
Frame moulding face width: 15 mm
Price of mount board per sheet: $7.00

You get

Mount size, long side: 370.00 mm
Mount size, short side: 320.00 mm
Mount at the bottom: 60.00 mm
Frame outer size, long side: 400.00 mm
Frame outer size, short side: 350.00 mm
Wall area the frame takes: 0.14 sq m
Area of mount board in square metres: 0.12 sq m
Visible image length: 242.00 mm
Visible image width: 192.00 mm
Visible image area: 46,464.00 sq mm
Share of the artwork hidden by the mount: 7.1%
How far the weighting lifts the image: 0.00 mm
Cost of one sheet of mount board: $7.00

A 370 by 320 mount and a 400 by 350 frame. The mount is 60 millimetres on every side, so the frame is more than twice the area of the print.

Open this example in the calculator →

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Frequently asked questions

How wide should a picture mount be?

Fifty to one hundred millimetres on each side is the usual range, and small pictures take proportionally more than large ones. A 200 by 250 millimetre print often looks best with an 80 to 100 millimetre mount, while a 500 by 700 millimetre picture rarely needs more than 70 or 80. The mount keeps the artwork off the glazing, which is essential for anything on paper, and it separates the image from the frame so the eye is not crowded.

What is a weighted mount or bottom weighting?

It is a mount with a deeper border at the bottom than at the sides and top, usually 10 to 20 percent deeper, which raises the image towards the optical centre of the mount. Without it, an even border looks as though the picture has slid down, because the eye reads the space above the image as excessive. It is most often used on landscape pictures, where the shape exaggerates the effect, and least on square ones. A 70 millimetre mount with 18 percent weighting becomes 82.6 millimetres at the bottom.

How much of the picture does a mount cover?

The mount window overlaps the paper by 3 to 6 millimetres on each edge, so a 500 by 400 millimetre sheet shows about 492 by 392 millimetres. That overlap is what holds the paper flat and stops it dropping out of the frame, so it is deliberate rather than a cutting error. If the printed image runs right to the edge of the sheet, that overlap will crop it, and the fix is a larger sheet or a float mount where the whole sheet is visible.

What size frame do I need for a mounted picture?

The frame is ordered by the mount size, not the picture size, because the rebate holds the mount and the glazing. A 500 by 400 picture with a 70 millimetre weighted mount needs a frame cut for about 640 by 553 millimetres, and with 22 millimetre moulding that is about 684 by 597 millimetres on the wall. Always allow a millimetre or two of clearance in the rebate so the mounted piece can be fitted without bowing.

Is a mount necessary?

For anything on paper, yes in practice. The mount holds the artwork away from the glazing so condensation cannot form on the surface, and it stops the paper from slumping inside the frame. For a canvas, or for a print that is dry mounted to a board, a mount is a design choice rather than a necessity, and a float mount or a plain frame with a spacer can look better. For an original work on paper, ask a framer about hinging and materials rather than taping it down.