Sizes for Corner and Side Triangles


This chart gives you the measurements for corner and side triangles for the most commonly used quilt-block sizes.

Finished Block Size Cut Size of Square for Corner Triangles Cut Size of Square for Side Triangles
2" 2 3/8" 4 1/4"
3" 3" 5 1/2"
4" 3 3/4" 7"
5" 4 1/2" 8 3/8"
6" 5 1/8" 9 3/4"
7" 5 7/8" 11 1/4"
8" 6 5/8" 12 5/8"
9" 7 1/4" 14"
10" 8" 15 1/2"
12" 9 3/8" 18 1/8"
14" 10 7/8" 21 1/8"
16" 12 1/4" 23 7/8"
18" 13 5/8" 26 3/4"
20" 15 1/8" 29 5/8"
24" 17 7/8" 35 1/3"

Cutting tip: It is easier to cut fabric smaller than make it bigger, so cut squares for corner and side triangles " - 1" larger and trim them down once your top is pieced.