Quilt block

Rail Fence quilt block

Three strips sewn side by side. Rotate alternate blocks a quarter turn and the strips lock into a woven basketweave across the whole quilt.

Also known as Roman Stripe unit.

Rail Fence is the most efficient pieced block there is — strip-piece a long set, crosscut, and you have blocks. It has been a beginner's first quilt and a scrap-user's standby for as long as rotary cutters have existed, and considerably longer before that.

Rail Fence cutting chart

Cut sizes include a ¼″ seam allowance: ½″ on squares and rectangles, ⅞″ on half-square triangles, and 1¼″ on quarter-square triangles. Pick a finished block size:

FabricShapeCut sizeQtyNotes
AccentRectangle12½" × 4½"1finishes 12" × 4"
BackgroundRectangle12½" × 4½"1finishes 12" × 4"
DarkRectangle12½" × 4½"1finishes 12" × 4"

How it goes together

Sew three strips along their length, press, then crosscut squares at the width of the strip set. Rotating every other block ninety degrees is what creates the woven effect.

Tips

  • Press all seams in the same direction within the strip set so the blocks nest predictably when rotated.
  • Sew the strip set with the pressing direction alternating between seams to stop the set bowing into a curve.
  • Value order matters more than colour: keep light, medium and dark consistent through every block or the weave breaks up.

How much fabric for a Rail Fence quilt?

Yardage for a whole quilt of Rail Fence blocks, computed the way the studio does it — every piece packed across a 40″ usable width with 10% added for waste.

Blocks set edge to edge at 12″ finished, no sashing or borders. Change any of that in the studio and the numbers update.
Quilt sizeBlocksFinishedTop fabricBackingBinding
Baby 36×481236" × 48"Background ⅝ yd · Dark ⅝ yd · Accent ⅝ yd2½ yd⅜ yd
Throw 60×723060" × 72"Background 1⅜ yd · Dark 1⅜ yd · Accent 1⅜ yd3⅞ yd½ yd
Queen 90×1087296" × 108"Background 3⅜ yd · Dark 3⅜ yd · Accent 3⅜ yd8¾ yd⅞ yd

What it looks like in a quilt

A single block only tells you half the story. Set sixteen of them together and the secondary pattern appears where the blocks touch:

Sixteen Rail Fence quilt blocks set four by four, showing the secondary pattern formed where the blocks meet
Four by four Rail Fence blocks, straight set with no sashing.

Rail Fence questions

How wide should Rail Fence strips be?

For a 12 inch finished block with three rails, each rail finishes at 4 inches, so cut strips at 4½ inches. Any number of rails works as long as they divide the block evenly.

Change one thing and every number follows

Resize the block, swap a fabric, add sashing — the cutting list and the yardage recalculate as you go. No spreadsheet, no re-doing the math.

Try it with Rail Fence