Mat Border Calculator for Picture Framing

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Fraction to Decimal Conversion Guide

1/8 = 0.125

1/4 = 0.25

3/8 = 0.375

1/2 = 0.5

5/8 = 0.625

3/4 = 0.75

7/8 = 0.875

1. Artwork

Enter dimensions of your artwork in inches, mm, or cm. Use decimals, not fractions. The calculator will subtract 1/4" from each side to eliminate an unsightly gap between artwork and mat.

width
height

2. Frame

Do not enter the overall size of your frame! Instead, measure from the frame's back to take into account the frame rabbet. These numbers will match the plexiglass size.

width
height

3. Mat Borders

By default, this calculator will center your artwork. But, you can choose to creatively offset your artwork here:

4. Single or Double

A double mat places a second mat between the top mat and artwork, creating a "reveal" border effect around your art.

Single Double

5. Double Mat Reveal

Define the width of the border created by your double mat.

1/8" 1/4" 1/2" 3/4"

Results

numbers are accurate, but drawing is not to scale

Top Mat

⟷ AA

BB
⟷

CC
⟷

⟷ DD

Mat Size	?x?	?x?
Opening Size	?x?	?x?
AA
BB
CC
DD

Your Mat

⟷ A

B
⟷

C
⟷

⟷ D

Mat Size	?x?	?x?
Opening Size	?x?	?x?
A
B
C
D