Authoritative data source & methodology
Primary standards: ISO 216 (A‑series paper sizes, 2007, reaffirmed) and common US sizes (Letter, Legal, Tabloid) as defined in ANSI/ASME Y14.1. All size data is used to populate presets and area calculations.
- ISO 216: International Organization for Standardization — A‑series dimensions (A0=841×1189 mm; each size halves the area).
- ANSI/ASME Y14.1: Decimal Inch Drawing Sheet Size & Format (US Letter 8.5×11 in, Legal 8.5×14 in, Tabloid 11×17 in).
“Tutti i calcoli si basano rigorosamente sulle formule e sui dati forniti da questa fonte.”
The formula explained
Effective piece size (including bleed, kerf, half‑gutter):
\[ w_e = w + 2\,b + k + g, \quad h_e = h + 2\,b + k + g \]
Available sheet area (with outer margins mt,r,b,l):
\[ W_a = W - (m_l + m_r), \quad H_a = H - (m_t + m_b) \]
Pieces fitting without rotation:
\[ n_1 = \left\lfloor \frac{W_a + g}{w_e} \right\rfloor \cdot \left\lfloor \frac{H_a + g}{h_e} \right\rfloor \]
Pieces fitting with 90° rotation:
\[ n_2 = \left\lfloor \frac{W_a + g}{h_e} \right\rfloor \cdot \left\lfloor \frac{H_a + g}{w_e} \right\rfloor \]
\( n_{up} = \max(n_1, n_2) \). Sheets required (with waste allowance \(p\%\)):
\[ S = \left\lceil \frac{Q}{n_{up}} \cdot (1 + p/100) \right\rceil \]
Sheet area: \( A_s = W \cdot H \) (converted to m² if needed). Project area: \( A = S\,A_s \). Weight: \( M = A\,\text{gsm}\,/1000 \) kg.
Glossary of variables
- W, H: sheet width & height.
- w, h: finished piece width & height.
- b: bleed per side.
- g: gutter between pieces.
- k: kerf (cut thickness).
- mt,r,b,l: outer margins (top, right, bottom, left).
- Q: target quantity.
- gsm: grams per square meter (paper density).
How it works: a step‑by‑step example
Suppose you need Q=250 square inserts, finished size 50×50 mm, no bleed, g=2 mm, k=0.5 mm, using A4 (210×297 mm), no outer margins, rotation allowed, paper 160 gsm, price €0.15/sheet, waste 5%.
- Effective piece size: \( w_e = h_e = 50 + 0 + 0.5 + 2 = 52.5\,\text{mm} \).
- Fit without rotation: \( \lfloor(210+2)/52.5\rfloor=4 \), \( \lfloor(297+2)/52.5\rfloor=5 \) → \( n_1=20 \).
- With rotation: same (square) → \( n_2=20 \). So \( n_{up}=20 \).
- Sheets: \( S = \lceil (250/20)\times1.05 \rceil = \lceil 13.125 \rceil = 14 \).
- Area per sheet: 0.210×0.297=0.06237 m². Total area: 14×0.06237=0.87318 m².
- Weight: 0.87318×160/1000 = 0.1397 kg (≈140 g).
- Cost: 14×€0.15 = €2.10.
FAQ
Should I count kerf and gutter together?
Yes—kerf represents material lost to cutting, while gutter is desired spacing. The calculator adds both so you don’t under‑estimate spacing.
What’s the difference between bleed and margins?
Bleed expands each piece to ensure edge‑to‑edge color after trimming. Margins reduce the usable sheet area at the outer edges.
Why does rotation change n‑up?
Rectangles often tile more efficiently when rotated 90°. We compute both orientations and take the maximum.
How accurate is the weight estimate?
Weight uses gsm×area. It’s accurate for paper stock; coatings, humidity, or thick boards may vary slightly.
How much waste should I allow?
For home crafting, 0–5% is typical. For production runs, 3–10% is common depending on setup and tolerances.
Tool developed by Ugo Candido. Content verified by CalcDomain Editorial Board.
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