A4 to A3 = 141% A5 to A4 = 141% From A3 to A1 = 200% A4 to A2 = 200%
Size and aspect ratio guide for A series paper sizes
A2 – 420 mm X 594 mm – 42m x 59.4cm – 15.52 inch x 23.39 inch -1:1.41. A3 – 297 mm X 420 mm – 29.7cm x 42cm- 11.69nch x 15.52 inch – 1:1.41. A4 – 210 mm X 297 mm – 21cm x 29.7cm – 8.26 inch x 11.69 inh -1:1.41.
Every 'A' size is double the previous size: A3 is twice the size of A4, and so forth. Remember that A8 is very small (about 2in x 3in) and A0 is big (nearly 3ft x 4ft).
A3 paper | 420 x 297 mm
A3 is half of a sheet of A2 and has a size of 420 x 297 mm. In a sheet of A3 are 2 sheets of A4, folded is the A4 size.
What is the aspect ratio of A4 paper? The aspect ratio of A4 paper is 1:1.41, or 1:√2. The same is true for the entire ISO 216 standard that is used in most parts of the world.
The ratio of the lengths of all metric papers (including A3) is 1 : 1.414 (root 2) so if you want your 16 : 9 print on A3, it'll end up at a width of 297mm x 420mm (length of paper) which means you're cropping approximately 54mm off each "short" end of your pic as 297 x 1.777 = 528mm @ 16 : 9.
The aspect ratio of A4, 1:1.414 is near the average of 1.5 for 2:3 and 1.333 for 3:4.
So for instance an A4 sheet measures 210mm x 297mm making its shortest edge 210mm long. An A3 sheet measures 420mm x 297mm. so to move up a size 210 x 2 = 420. This gives an A3 sheet the flat size equivalent of exactly 2 A4 sheets.
Standard Paper Sizes
Size A4 has its shortest edge (210mm) doubled to be the longest edge of A3 (420mm).
Assuming your printer can print to A3, select that paper size on the Paper tab of Page Setup. Then, on the Margins tab of Page Setup, under "Multiple pages," choose "2 pages per sheet." This will put two A4 pages on the A3 sheet, but you will see them just the same as before (you won't see them side by side).
A3 to A4 = 71%
The A3 size print measures 29.7 x 42.0cm, 11.69 x 16.53 inches, if mounted 40.6 x 50.8cm, 15.98 x 20 inches. The A4 size print measures 21.0 x 29.7cm, 8.27 x 11.69 inches, if mounted 30.3 x 40.6cm, 11.93 x 15.98 inches.
International paper size 'A3', portrait orientation, is 297 mm wide x 420 mm long (11.69″ x 16.54″); aspect ratio 1:1.414.
The aspect ratio (width:height) of A3 paper is 1:1.4142 (1:√2).
The measurements of A4 paper are 8.27 x 11.67 inches and they conserve the ratio between width and length of √2.
An A3 piece of paper measures 297 × 420 mm or 11.7 × 16.5 inches. Cutting it in half will create two A4 sheets of paper.
A5: 148 x 210 mm
A5 paper is half the size of A4. This is the size of many: private letters, invitations. commercial memos.
16:9 Ratio Defined
Examples of 16:9 ratios are 16 inches wide by 9 inches high, 32 widgets wide by 18 widgets high, and 1920 pixels wide by 1080 pixels high.
Common Printing Aspect Ratios
Some popular print sizes for the 3:4 ratio includes 30 x 40 inches and 18 x 24 inches. 16 x 20 inches is the most popular print size for a 4:5 aspect ratio. There are some other popular print aspect ratios like 8.5 x 11 inches and 11 x 17 inches.
A3 and A4 have widely used papers all around the world. The main difference between these two paper sizes is the dimension. A3 size is equal to two A4 paper sheets.
The height/width ratio remains constant for all sizes: 1:1.41 or the square root of 2. The dimensions always get rounded to the nearest millimeter.
What is A3 size in pixels? If you're creating artwork for a poster, or indeed anything that will be printed, you should always create it at 300dpi (dots per inch). This will ensure your design reproduces correctly without any visible pixilation. At 300dpi, A3 artwork (without bleed) should be 3508 x 4961 pixels.