What border width should I use?

The standard border width for most artwork is 6-8cm. Larger pieces may suit 8-10cm borders. A wider border gives the artwork room to breathe. A weighted bottom border (2-3cm extra) is traditional and gives a visually balanced mount.

What is a weighted bottom border?

A weighted bottom adds extra width to the bottom border (typically 1-3cm). This is a traditional framing convention that counteracts the optical illusion of the artwork appearing to sink in an equal-border mount. The result looks more balanced to the eye.

What is the reveal overlap?

The reveal overlap is how much the mount window edge covers the artwork edge. Typically 2-4mm on each side. This hides any uneven artwork edges and prevents the artwork from falling through the window opening.

What angle should the mount be cut at?

A 45° bevel cut is standard for picture framing mounts. The bevel reveals a thin white line of the mount board core, creating an elegant transition between the mount and the artwork. Always cut with a sharp blade for clean bevels.

ArtCalcs

Mount Board Calculator \u2014 Mat Board Cutting Dimensions

Calculate mount board outer dimensions, window cut size, backing board and frame size for picture framing.

Artwork Width

Width measurement

Artwork Height

Height measurement

Mount StyleMount/mat board specifications

Border Width

Width measurement

Frame Rebate Depth

Depth of frame lip that holds the mount

How We Calculate This

Calculation Method

Window cut = Artwork size \u2013 (Overlap \u00D7 2) on each dimension
Outer mount = Window + Border on each side (+ bottom extra if weighted)
Backing board = Same as outer mount dimensions
Frame size = Outer mount + (Rebate \u00D7 2) on each dimension

Frequently Asked Questions

Related Calculators

Frame Size Calculator

Calculate outer frame dimensions based on artwork size and moulding width. Includes rebate allowance and overall measurements.

Mat Board Calculator

Work out mat board dimensions and opening size with correct border widths. Includes weighted bottom border for professional results.

Glass Size Calculator

Calculate the glass or acrylic glazing size needed for your picture frame. Covers standard glass, non-reflective and UV-filtering.

Frame Moulding Calculator

Calculate the total length of frame moulding needed including mitre joint waste allowance. Free online calculator for framers.

Backing Board Calculator

Work out backing board dimensions and material needed for your picture frame. Covers MDF, foam core, corrugated board and acid-free options.

Last updated: March 2026

All calculations are estimates. Always verify quantities before purchasing materials.