Rail Fence Quilt Block — Cutting Chart for Any Size

4 fabrics · Difficulty 1 of 5

Rail Fence is a 4×4 block of 4 pieces. Cut sizes for 4″, 8″, 12″, 16″, 20″ are below; for any other size it divides into cleanly, type the size and the chart recomputes.

Set the finished size

At a glance

Grid
4×4
Pieces you cut
4
Difficulty
1 of 5 — first block How this is scored

Set the size

Cutting sizes for a 12″ finished block.
Strips — Fabric A
12½ × 3½″
Strips — Fabric B
12½ × 3½″
Strips — Fabric C
12½ × 3½″
Strips — Background
12½ × 3½″
Rail Fence quilt blockA 4 by 4 grid of 4 units: 4 strips. 4 pieces in total.
Rail Fence — a 4 by 4 grid of 4 units: 4 strips. 4 pieces in total.

Reading focusParallel strip outlines expose the strip-set geometrystrip

Construction lattice
4 modules wide × 4 modules high
Unit mix
strip
Piece count
4 to cut · 4 in the diagram

Cut these pieces

Column headings are the FINISHED block size — the size it will be once it is sewn. Every number in the table is the size to CUT, which includes ¼″ of seam allowance on each edge. Rows that are subcut on a diagonal are cut larger still, so the allowance survives the extra cuts.

Scroll sideways to see every size.

Cutting sizes for Rail Fence, by finished block size
Patch4″8″12″16″20″
Strips — Fabric ACut 14½ × 1½″8½ × 2½″12½ × 3½″16½ × 4½″20½ × 5½″
Strips — Fabric BCut 14½ × 1½″8½ × 2½″12½ × 3½″16½ × 4½″20½ × 5½″
Strips — Fabric CCut 14½ × 1½″8½ × 2½″12½ × 3½″16½ × 4½″20½ × 5½″
Strips — BackgroundCut 14½ × 1½″8½ × 2½″12½ × 3½″16½ × 4½″20½ × 5½″

Read the block

Match each fabric letter in the diagram to the same fabric name in the cutting table. The caption describes the generated geometry in text.

Fabrics in this block

  • A — gold
  • B — turkey red
  • C — teal
  • BG — background

Which sizes divide cleanly

Scroll sideways to see every column.

Which finished sizes each grid divides into cleanly
GridDivides cleanly atThe first few sizes
2×2every 1″1″, 2″, 3″, 4″, 5″, 6″ …
3×3every 1½″1½″, 3″, 4½″, 6″, 7½″, 9″ …
4×4this blockevery 2″2″, 4″, 6″, 8″, 10″, 12″ …
5×5every 2½″2½″, 5″, 7½″, 10″, 12½″, 15″ …
7×7every 3½″3½″, 7″, 10½″, 14″, 17½″, 21″
  • A 5-patch block at 12″ would need 2.4″ units, which is not a mark on any ruler. Try 10″ or 12½″ instead — Sister's Choice is the 5-patch block on this site.
  • A 7-patch block at 12″ would need 1.714…″ units, which is not a mark on any ruler. Try 10½″ or 14″ instead — Bear's Paw is the 7-patch block on this site.

More about the sizes that do not divide cleanly

The sizes in between

Every whole-inch Rail Fence size from 4″ to 20″ can be cut accurately on its 4×4 grid.

These sizes divide cleanly but sit between the main chart's columns — the same computed cuts, published here so they exist on paper too. Any other clean size still computes in the size input above.

Column headings are the FINISHED block size — the size it will be once it is sewn. Every number in the table is the size to CUT, which includes ¼″ of seam allowance on each edge. Rows that are subcut on a diagonal are cut larger still, so the allowance survives the extra cuts.

Scroll sideways to see every size.

Cutting sizes for Rail Fence — between sizes, by finished block size
Patch6″10″14″18″
Strips — Fabric ACut 16½ × 2″10½ × 3″14½ × 4″18½ × 5″
Strips — Fabric BCut 16½ × 2″10½ × 3″14½ × 4″18½ × 5″
Strips — Fabric CCut 16½ × 2″10½ × 3″14½ × 4″18½ × 5″
Strips — BackgroundCut 16½ × 2″10½ × 3″14½ × 4″18½ × 5″

About this block

Pieces in the finished block
4
Unit types
strip
Divides cleanly at
2″, 4″, 6″, 8″, 10″, 12″, 14″, 16″, 18″ and 20″ finished.
Also known as
Fence Post, Snake Fence, Endless Stairs, London Stairs, Virginia Worm Fence
Fabric for one 12″ block
1½ yd total, rounded up to the nearest ⅛ yard, assuming 40″ of usable width.

Sew the strips in fabric order and press all the seams one way; a bowed strip set here becomes a wobbly fence in the quilt. Nothing inside the block turns — the zigzag arrives at the quilt top, where alternate blocks rotate against each other — so keeping the fabric order consistent from block to block is what preserves the weave.

Piecing order

  1. Lay out row 1 of 4 and sew its pieces together, left to right.

  2. Lay out row 2 of 4 and sew its pieces together, left to right.

  3. Lay out row 3 of 4 and sew its pieces together, left to right.

  4. Lay out row 4 of 4 and sew its pieces together, left to right.

  5. Join the 4 rows, matching the seams.

Cutting oversize

Nothing in this block needs cutting oversize: every piece is cut straight to its exact size, so sew an accurate quarter inch and it comes out true. If you like trimming room anyway, the reasoning is on how to square up a quilt block.

History

Every recorded name describes what the strips do: fence names — Snake Fence, Virginia Worm Fence — when the block zigzags like a country fence line, staircase names — Endless Stairs, London Stairs — when it is set flat. Colourways carried names of their own: red, white and blue made Spirit of St. Louis, and purple on a light ground made Roman Stripe, after the stripe on a senator's robe.

Sources: Virginia Fibre Arts — Rail Fence history.


Common questions

What size can I make Rail Fence?

Any size it divides cleanly: 2″, 4″, 6″, 8″, 10″, 12″, 14″, 16″, 18″ and 20″ finished. The chart above carries 4″, 8″, 12″, 16″, 20″ ready-worked, and the size input computes any other clean size without you doing arithmetic — every value computed by Quilt Block Atlas, none transcribed.

How many pieces are in a Rail Fence block?

4 — and you cut exactly that many, because every piece in this block is used whole. The chart's quantities add up to the diagram.

What sizes does a 4×4 block divide into cleanly?

2″, 4″, 6″, 8″, 10″, 12″, 14″, 16″, 18″ and 20″ finished. The step is half the grid this block's cutting sizes are computed on, and the clean-size table above marks this block's row with the other families beside it.

Is Rail Fence good for a beginner?

Yes — it scores 1 of 5, first block, on this site's computed scale: 4 pieces, with the strip as its hardest unit. The scoring rule, and every block ranked by it, is on the difficulty page linked above.

How do finished size, sewn unfinished/trim size, and starting cut size differ?

Finished size is 12″ after the block is sewn into surrounding seams. Its sewn unfinished/trim size is 12½″ before those outer seams, derived with the plain-square allowance. Starting cut size is the method-specific input listed in the chart. Starting cut size equals the unfinished outer target only for a plain square or rectangle workflow; it is not generally the same for pieced triangle units.


Keep going


Measure this square before you cut. It must be exactly 1 inch. If it isn't, your printer scaled the page — reprint at 100% or "Actual size", not "Fit to page".

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