Picture Frame Calculator

What This Calculator Does

This tool calculates the total outer dimensions of a picture frame based on your artwork size and the desired border (mat) width. It answers a simple but critical question: what size frame do I actually need to buy?

You provide the width and height of your picture, plus the border width you want around it. The calculator returns the total frame width and height, accounting for the border on all four sides.

How the Calculation Works

The math is straightforward. The border width is added twice to each dimension — once for the left and once for the right (for width), and once for the top and once for the bottom (for height).

Formula:

• Frame Width = Picture Width + (2 × Border Width)
• Frame Height = Picture Height + (2 × Border Width)

This assumes a uniform border on all sides. If you plan to use different border widths on each side, this calculator provides a baseline that you can adjust manually.

How to Use It

1. Measure your picture or artwork width and height in inches or centimeters.
2. Decide how much border (mat) you want around the picture. Common border widths range from 1 to 4 inches.
3. Enter all three values into the calculator.
4. Read the resulting frame dimensions. This is the minimum frame size you need.

If you plan to use a mat with a window cutout, the border width you enter should match the visible mat width around the artwork.

Example

You have a photo that is 8 inches wide by 10 inches tall. You want a 2-inch border around it.

• Frame Width = 8 + (2 × 2) = 12 inches
• Frame Height = 10 + (2 × 2) = 14 inches

You need a frame that fits a 12 × 14 inch opening. Standard frame sizes may not match exactly, so you may need a custom frame or adjust your border width to fit a standard size.

Understanding the Result

The output gives you the outer dimensions of the frame's interior opening — the space the picture and mat will occupy together. This is the size you use when selecting or ordering a frame.

Note that the calculator does not account for:

• The thickness of the frame molding itself (which adds to the overall exterior size of the frame).
• The depth of the frame (important for thicker artwork or stacked mats).
• Any additional backing or mounting materials.

Always confirm your measurements against the frame manufacturer's specifications before purchasing.

Common Mistakes

• Forgetting the border applies to both sides. A 2-inch border adds 4 inches total to each dimension, not 2.
• Confusing border width with mat width. The border width is the visible mat area around the artwork, not the total mat size including the window overlap.
• Assuming standard frame sizes will fit. Standard frames are often nominal sizes. Always verify the actual opening measurement.
• Not accounting for the frame's rabbet depth. The lip that holds the artwork in place can overlap the mat slightly, so your artwork may need to be slightly smaller than the opening.

Practical Use Cases

• Custom framing artwork: Determine the exact frame size needed before ordering a custom frame or mat.
• Buying pre-made frames: Check whether a standard frame size will work with your desired border width.
• Planning gallery walls: Calculate frame sizes for multiple pieces to ensure consistent border widths across a collection.
• DIY framing projects: Get accurate dimensions before cutting mat board or selecting a frame from a craft store.