Quilt block

Diagonal Stripe quilt block

Half-rectangle triangles all leaning the same way, so the seams line up block to block and the quilt reads as one set of long diagonal bands.

Also known as Bias stripe, Slant.

A diagonal stripe is what you get when you stop alternating. Quilters have arrived at it accidentally for two centuries — set any directional block all one way and it happens — and deliberately since the modern-quilt movement made large, calm, graphic tops fashionable again.

Diagonal Stripe 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
BackgroundHRT rectangle, “\” diagonal7" × 13"4finishes 6" × 12" — sew the diagonal, then trim to 6½" × 12½"
DarkHRT rectangle, “\” diagonal7" × 13"4finishes 6" × 12" — sew the diagonal, then trim to 6½" × 12½"

How it goes together

Four HRTs, all the same handedness, in a 2 × 2. Because nothing mirrors, this is the easiest block in the half-rectangle family: one stack of cutting, one stack of pressing.

Tips

  • This is the block to start with if you have never sewn an HRT. Every unit is identical, so a mistake is a consistent mistake and easy to correct.
  • The stripe angle comes from the cell aspect, not the block size. A 1:2 cell gives roughly 27°; try 3:4 in the block editor for a steeper, busier stripe.
  • Use it as a border. A single row of diagonal-stripe blocks makes a barber-pole edge that costs almost nothing to piece.

How much fabric for a Diagonal Stripe quilt?

Yardage for a whole quilt of Diagonal Stripe 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 36×48636" × 48"Background 1¾ yd · Dark 1¾ yd2½ yd⅜ yd
Throw 60×721560" × 72"Background 4⅜ yd · Dark 4⅜ yd3⅞ yd½ yd
Queen 90×1084096" × 120"Background 11⅝ yd · Dark 11⅝ yd10¾ 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 Diagonal Stripe quilt blocks set four by four, showing the secondary pattern formed where the blocks meet
Four by four Diagonal Stripe blocks, straight set with no sashing.

Diagonal Stripe questions

How do I make the stripes wider?

Make the block bigger, or reduce the number of columns. The stripe width is the finished cell width, so a 12 inch block on a 2 × 2 grid gives 6 inch bands.

Can I get the stripes to run the other way?

Yes — use the Flip tool on the quilt, or mirror the block in the editor. Flipping alternate columns instead gives you a zigzag.

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 Diagonal Stripe