search

Found

info Overview

Enter your frame opening and artwork size to get exact top, bottom, left and right mat borders plus the window cutout, in even or bottom-weighted layout.

📘 How to Use

  1. Enter the frame opening size (width by height)
  2. Enter your artwork size and the overlap per side
  3. Pick an even or bottom-weighted border layout and read the four borders and window cutout

Picture Frame Mat Calculator

× in
× in

The outer size of the print or art itself

in

How far the mat covers each artwork edge. 1/8–1/4 in (about 0.12–0.25 in) is typical

Bottom-weighted widens the bottom border by ~20% to raise the optical center

grid_view Related

Article

Picture Frame Mat Calculator｜All Four Borders and the Window Cutout

Enter your frame opening and artwork size to get the exact top, bottom, left and right mat border widths plus the window cutout the mat shows. It supports both an even layout and a bottom-weighted layout that widens the bottom border to balance the eye.

💡 About this tool

The two questions that trip up every DIY framer are "how big do I cut the window?" and "how wide should the borders be?" The window has to be a little smaller than the art so the mat lip holds the edges down; cut it at the exact art size and the print can slip back through or show the mount board around the gap. This tool sets the cutout to "artwork − overlap × 2" and then splits the leftover space into borders using "(opening − cutout) ÷ 2", so you see the finished numbers before you touch a mat cutter. Switch to bottom-weighted and it shifts the vertical split downward, correcting the optical illusion where a perfectly centered print looks like it is sinking.

🧐 Frequently Asked Questions

How much smaller than the art should the window be? The mat should overlap each edge of the artwork by at least 1/8 in (about 3 mm) so the edges do not peek through or fall through. A 1/4 in lip is common; for signed work some framers keep the bottom shallow to show the signature.

What is a normal mat border width? Borders under one inch are discouraged because they show damage easily; widths from one to three inches are standard. Smaller art often looks better with a wider border so it does not get lost.

When should I use bottom-weighting? Use it for tall pieces or art hung high on a wall. A print centered with equal top and bottom borders appears to drop, so a slightly wider bottom raises the optical center. The amount varies by shop; this tool uses about 20% as a rule of thumb.

Why does it say the cutout is larger than the frame? If the window cutout reaches or exceeds the frame opening, the borders would be zero or negative, which cannot be built. Reduce the artwork size or increase the overlap to fix it.

📚 Mat Cutting Facts

Mat board does more than decorate: a window mat keeps the glazing from touching and sticking to the artwork, which is why conservation framing almost always includes one. The standard "subtract twice the border, divide by two" math is the same routine framers run by hand, and it is exactly what dedicated mat cutters from brands like Logan have automated with on-tool border guides. Getting the cutout a hair smaller than the art is the single step beginners skip most often.