CalcDomain

Authoritative data source & methodology

Primary references: ISO 216 paper sizes (A‑series) and US Letter specification; standard print bleed guidance from professional sources; common A‑style envelope sizes used in stationery.

  • ISO 216 — A‑series dimensions (e.g., A4 = 210 × 297 mm; A5 = 148 × 210 mm). Tutti i calcoli si basano rigorosamente sulle formule e sui dati forniti da questa fonte.
  • US Letter — 8.5 × 11 inches.
  • Bleed — Typical 0.125 in (≈3 mm) recommendation; always confirm your printer’s spec.
  • A‑style envelopes — A2, A6, A7 mappings for greeting card standards.

The formula explained

Let sheet size be \(S_w \times S_h\), unprintable margin per edge \(m\), bleed per edge \(b\), kerf (gap) between pieces \(k\).
Let unfolded card piece be \(C_w \times C_h\). For a single fold with side fold: \(C_w = 2\,W\), \(C_h = H\). For top fold: \(C_w = W\), \(C_h = 2\,H\). For flat panels: \(C_w = W\), \(C_h = H\).
Effective sheet area: \(S'_w = S_w - 2m\), \(S'_h = S_h - 2m\).
Place rectangles with gutters \(g = k + 2b\) in a grid.
Rows (no rotation): \(r = \left\lfloor \dfrac{S'_h + k}{C_h + g} \right\rfloor\), columns: \(c = \left\lfloor \dfrac{S'_w + k}{C_w + g} \right\rfloor\).
If rotation allowed, compute \(r^*, c^*\) swapping \(C_w, C_h\); choose the max \(N = \max(rc, r^*c^*)\).
Waste: \(\text{waste} = 1 - \dfrac{N\,(C_w\,C_h + g\,C_w + g\,C_h + b^2)}{S'_w S'_h}\) (approx. area‑based with gutters & bleed).

Glossary of variables

  • Sheet width/height — Size of your paper sheet after any printer margins are excluded.
  • Unprintable margin (m) — Non‑imageable border many desktop printers require.
  • Bleed (b) — Extra image beyond trim to avoid white edges after cutting.
  • Kerf (k) — Cutter blade thickness / safety gap between pieces.
  • Fold mode — Single fold creates an unfolded piece twice one dimension.
  • Allow rotation — Try orienting pieces 90° to improve yield.

How it works: a step‑by‑step example

Example: A6 folded card on A4 with 3 mm bleed, 2 mm kerf, side fold

Finished A6 card (W×H = 105×148 mm). Single fold side → unfolded piece 210×148 mm. A4 sheet 210×297 mm with 0 mm unprintable margin. Compute gutters: g = 2b + k = 2×3 + 2 = 8 mm. Grid (no rotation): rows = ⌊(297+2)/(148+8)⌋ = 1; cols = ⌊(210+2)/(210+8)⌋ = 1 ⇒ 1 per sheet. With rotation: rows = ⌊(297+2)/(210+8)⌋ = 1; cols = ⌊(210+2)/(148+8)⌋ = 1 ⇒ still 1. Waste ≈ 1 − area_used/area_sheet.

Frequently asked questions

What’s the difference between bleed and kerf?

Bleed extends artwork beyond the trim; kerf is the cutting clearance. Use both to avoid white edges and to prevent nicking the piece when cutting.

How do I get the score line position?

The SVG map adds a dashed center line through each folded piece; that is your score location before folding.

Which envelopes fit common card sizes?

A2 fits 4.25×5.5 in cards, A6 fits 4.5×6.25 in, A7 fits 5×7 in. Metric equivalents are shown in the calculator when you switch units.

Why do I get 0 cards per sheet?

Check that your unfolded piece plus gutters isn’t larger than the imageable sheet. Reduce bleed/kerf or allow rotation.

Can I use 12×12 scrapbooking sheets?

Yes—select the 12×12 preset or type 12 in and switch units to inches. The layout engine works the same way.

Tool developed by Ugo Candido. Content verified by the CalcDomain Editorial Board.
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