An A1 page (landscape) is 841 x 594 mm. The sheet is A3, 297 x 420 mm, a built-in preset in FitPrint. The layout below is what FitPrint produces with its defaults: Fit most packing, Original size scaling, a 5 mm gap between items and a 5 mm side margin. At the default gap and margin the item does not fit inside the usable area of the sheet, so Original size scales it down to 35.4 percent and places it at 297.35 x 210.02 mm. It is never cropped or split across sheets.

Where each item lands

Positions are millimetres on the A3 sheet as FitPrint wrote them, with y measured from the bottom edge.

x (mm)	y from bottom (mm)	Width (mm)	Height (mm)
-0.18	104.99	297.35	210.02

What other settings place

Settings	Items per sheet	Placed size
Fit most, 5 mm gap and 5 mm margin (default)	1	297.35 x 210.02 mm (35.4 percent)
Stack, 5 mm gap and 5 mm margin	1	297.35 x 210.02 mm (35.4 percent)
Fit most, no gap or margin	2	297.35 x 210.02 mm (35.4 percent)
Fit most, 10 mm gap and 10 mm margin	1	297.35 x 210.02 mm (35.4 percent)
Stack, no gap or margin	2	297.35 x 210.02 mm (35.4 percent)

Turned portrait, 1 fit: A1 pages on A3.

What the status line says

With 1 A1 page (landscape) in the list, FitPrint's status line reads exactly "1 item · 1 A3 sheet". Add one more and it reads "2 items · 2 A3 sheets": the extra item starts a new sheet rather than shrinking anything.

How to lay this out in FitPrint

Drag your files in. Open FitPrint and drag your A1 page (landscape) files onto the window. Each file appears in the list with its size in the caption.
Choose the A3 sheet. Click A3 in the sheet preset grid. FitPrint then lays the items out on a 297 x 420 mm sheet.
Keep scaling on Original size. At the default 5 mm gap and 5 mm side margin, this A1 page (landscape) does not fit inside the usable area of the A3 sheet, so Original size scales it down to 35.4 percent (297.35 x 210.02 mm) to fit. It is never cropped or split across sheets.
Leave packing on Fit most. Fit most packs as many items per sheet as fit. At the default gap and margin this one does not fit inside the usable area, so FitPrint scales it to 35.4 percent and places one per sheet.
Change the gap or side margin only if you need to. The defaults are a 5 mm gap and a 5 mm side margin. The settings table on this page shows what every other recorded setting places on this sheet.
Export and print at actual size. Click Export PDF, then set Scale to 100 percent and Pages per Sheet to 1 in the print dialog so nothing re-scales the exported file.

A1 page (landscape) on A3: scaled to 35.4 percent to fit

Where each item lands

What other settings place

What the status line says

How to lay this out in FitPrint

Related layouts