How wide to cut fabric for double‑fold bias tape

Cut your fabric strips four times the desired finished width for double-fold bias tape. For example, a 1/2 inch finished double-fold needs 2 inch-wide strips; a 3/8 inch finished double-fold needs 1.5 inch-wide strips (Seamwork: How to Make Bias Tape; Closet Core Patterns: How to Sew Double-Fold Bias Tape).

Single fold vs double fold: what the width refers to

Double-fold bias tape is single-fold tape pressed in half again. The 4× rule works because the final fold halves the already single-folded tape. By contrast, single-fold bias tape starts from strips cut at 2× the desired finished width (Seamwork: How to Make Bias Tape). Pre-made sizes you’ll see include 3/8 inch and 1/2 inch finished double-fold (Closet Core Patterns), and many notions aisles label standard double-fold around 1/4 inch with extra-wide at 1/2 inch (American Sewing Guild: Bias Tape Basics).

Worked examples you can copy

• Finished 1/4 inch double-fold → cut 1 inch strips (1/4 × 4)
• Finished 3/8 inch double-fold → cut 1.5 inch strips (3/8 × 4)
• Finished 1/2 inch double-fold → cut 2 inch strips (1/2 × 4)

These pairings match common garment and quilt binding sizes (Closet Core Patterns; American Sewing Guild).

Cut and press: the short, reliable sequence

1) Cut on the true bias for curves

For edges that curve, cut strips at 45 degrees to the grain (true bias) so the tape eases smoothly. If you’re new to grainlines and bias, our explainer can help: What does fabric grain mean? (Seamwork).

2) Join and press to single fold

Sew strip joins diagonally, press seams open, then press both long raw edges toward the center to make single-fold tape. A bias-tape maker speeds this and keeps widths even (Seamwork).

3) Press to double fold

Fold the single-fold strip in half lengthwise and press. Use a pressing cloth if your fabric shows shine; see our quick guide: Should a pressing cloth be wet or dry?

Choosing a bias‑tape maker size

Bias‑tape makers are labeled by the single‑fold width they produce. To get a given finished double‑fold width, choose a maker that equals the single‑fold width (which is half your cut strip). Example: for 1/2 inch finished double‑fold, cut 2 inch strips and run them through a 1 inch (25 mm) maker to create 1 inch single‑fold before the final half‑fold (Whipstitch: Bias Tape Makers & Measurements).

Quick comparison: single‑fold vs double‑fold math

• Single‑fold desired width → cut 2× that width.
• Double‑fold desired width → cut 4× that width.

Example: a 1/2 inch single‑fold facing uses 1 inch strips; a 1/2 inch double‑fold binding uses 2 inch strips (Seamwork).

Why testing helps

Pressing technique and fabric thickness can nudge widths narrower or wider. Make a short sample first, then adjust your cut width or pressing to lock in the target size (Closet Core Patterns).

FAQ

Do some tools need a different cut width than the 4× rule?

Most hand‑pressed or maker‑pressed double‑fold works with 4×, but some tools provide a cut‑width chart. If a manufacturer chart differs, follow it and test a short length first (Whipstitch).

What finished widths are commonly offered pre‑made?

You’ll frequently see 3/8 inch and 1/2 inch finished double‑fold in garment and quilt tutorials (Closet Core Patterns). Many packaged notions also label a standard double‑fold near 1/4 inch and an extra‑wide at 1/2 inch (American Sewing Guild).