SeeMyQuilt
Strips & logs · Confident beginner · 18" finished

18 inch Roman Square quilt block

Cutting chart, piecing steps and yardage for a Roman Square block that finishes at 18". The block is a 9 × 9 grid and each cell finishes at 2".

Finished block 18" × 18". Unfinished 18 1/2" × 18 1/2".

Cutting chart for one block

FabricCutSizeThen
Main16 rectangles6 1/2" × 2 1/2"–
Background8 rectangles6 1/2" × 2 1/2"–
Accent1 square6 1/2" × 6 1/2"–

How to piece it

  1. Cut the pieces in the chart above. All measurements include a 1/4" seam allowance.
  2. Lay all the pieces out as in the diagram. The block is a 9 × 9 grid, and each cell finishes at 2". Sew neighbouring pieces into sections, then the sections into rows, pressing seams in opposite directions from row to row.
  3. Join the rows. The block should measure 18 1/2" now and 18" once it is sewn into the quilt.

Yardage for a quilt of 18" Roman Square blocks

Quilt sizeBlocksFinished sizeMainBackgroundAccentBorder & bindingBacking
Baby2 × 2 (4)42" × 42"7/8 yd1/2 yd1/4 yd7/8 yd3 yd
Lap2 × 3 (6)42" × 60"1 1/4 yd5/8 yd1/4 yd1 yd4 yd
Throw3 × 4 (12)60" × 78"2 1/2 yd1 1/4 yd1/2 yd1 3/8 yd5 yd
Twin4 × 5 (20)78" × 96"4 1/8 yd2 1/8 yd7/8 yd1 3/4 yd8 3/4 yd
Queen5 × 5 (25)96" × 96"5 1/8 yd2 5/8 yd1 yd1 7/8 yd8 3/4 yd
King6 × 6 (36)114" × 114"7 3/8 yd3 3/4 yd1 1/4 yd2 1/8 yd10 1/4 yd

Blocks side by side with a 3" border, 2 1/2" binding, 42" usable width and 10% extra.

What a lap quilt looks like

2 × 3 blocks, 42" × 60" with border.

This diagram uses plain colors. To see the quilt in your own fabrics, with sashing or on point, use the tool below: tap a fabric and choose a photo.

9" Roman SquareAll Roman Square sizes

See it in your own fabrics

1. Your fabrics (tap a fabric, then choose a sample or your own photo)
2. Block
3. Quilt size
4. Block size
5. Setting

What to buy

FabricYardageCut

Based on 42" usable fabric width, 1/4" seams and 10% extra. Your photos stay on your device.

Questions

What do I cut for a 18 inch Roman Square block?

16 main rectangles at 6 1/2" × 2 1/2"; 8 background rectangles at 6 1/2" × 2 1/2"; 1 accent square at 6 1/2" × 6 1/2".

What size is the block before it is sewn into the quilt?

18 1/2" square. It finishes at 18" once the seams on all four sides are sewn.

How much fabric for a throw quilt of 18 inch Roman Square blocks?

12 blocks make a 60" × 78" quilt. Buy 2 1/2 yd of main, 1 1/4 yd of background, 1/2 yd of accent and 1 3/8 yd of border & binding, plus 5 yd for the backing.