A1 at 150 DPI in pixels: 3508 × 4967

A1 at 150 DPI is 3508 × 4967 pixels

A1 (594 × 841 mm) at 150 DPI is 3508 × 4967 pixels, which is 17 megapixels.

Portrait	3508 × 4967 pixels
Landscape	4967 × 3508 pixels
With 3 mm bleed	3543 × 5002 pixels
Megapixels	17
Aspect ratio	1.42:1 (1 to √2 before rounding)
File size	50 MB as uncompressed 8-bit RGB; a JPEG or PNG is smaller
Paper size	594 × 841 mm (23.39 × 33.11 in)

Portrait

3508 × 4967 pixels

Landscape

4967 × 3508 pixels

With 3 mm bleed

3543 × 5002 pixels

Megapixels

Aspect ratio

1.42:1 (1 to √2 before rounding)

File size

50 MB as uncompressed 8-bit RGB; a JPEG or PNG is smaller

Paper size

594 × 841 mm (23.39 × 33.11 in)

The working

Pixels are inches multiplied by the resolution, and an inch is 25.4 mm.

Width: 594 mm ÷ 25.4 = 23.386 in; 23.386 in × 150 = 3,507.9, which rounds to 3508 pixels.
Height: 841 mm ÷ 25.4 = 33.11 in; 33.11 in × 150 = 4,966.5, which rounds to 4967 pixels.

Bleed is extra image past the trim line, so that a cut that lands slightly off still leaves ink to the edge. Print shops usually ask for 3 mm on every side of an A-series page, which makes the file 3543 × 5002 pixels.

Is your photo big enough?

To fill A1 at 150 DPI an image needs at least 3508 × 4967 pixels. Cropped to fill the sheet:

A 12 megapixel phone photo (4000 × 3000) gives 121 DPI: short of 150, so it would be upscaled or printed softer.
A 24 megapixel camera photo (6000 × 4000) gives 171 DPI: enough.
A 48 megapixel photo (8000 × 6000) gives 242 DPI: enough.

At 150 DPI the pixels of a print blend together from about 22.9 inches (58 cm) away. 150 DPI is a common minimum for posters and large prints seen from a step or two away, and a usual setting for scanning documents that only need to be read.

A1 at other resolutions

Resolution	Pixels	With bleed	Megapixels	Uncompressed
72 DPI	1684 × 2384	1701 × 2401	4	11 MB
96 DPI	2245 × 3179	2268 × 3201	7.1	20 MB
100 DPI	2339 × 3311	2362 × 3335	7.7	22 MB
150 DPI	3508 × 4967	3543 × 5002	17	50 MB
200 DPI	4677 × 6622	4724 × 6669	31	89 MB
240 DPI	5613 × 7946	5669 × 8003	45	128 MB
300 DPI	7016 × 9933	7087 × 10004	70	199 MB
400 DPI	9354 × 13244	9449 × 13339	124	354 MB
600 DPI	14031 × 19866	14173 × 20008	279	797 MB
1200 DPI	28063 × 39732	28346 × 40016	1,115	3.12 GB

A1 is half of A0, a common size for posters, plans and flip charts. See A1 in pixels at every resolution or everything at 150 DPI.

A1 at 150 DPI is 3508 × 4967 pixels

The working

Is your photo big enough?

A1 at other resolutions

Other sizes at 150 DPI