Maximum size of digital cameras and printable photos

Printing size (INCHES) The size of the file (about) requires the minimum resolution of the Photo size
(1 inch/2 inch) 150-200kb 640x480 (0.3 million) 2.5x3.5/5.3x3.5
(5 × 3. 5 inch) 3R 500-550kb 1280x960 (1.2 million) 12.70 × 8.89
(6 × 4 inch) 4R 600-650kb 1280x1024 (1.3 million) 15.24 × 10.16
(7 × 5 inch) 5R 800-900kb 1600x1200 (2 million) 17.78 × 12.70
(8x6 inch) 6R 1-1.2 MB 1900x1280 (2.4 million) 20.32x15.24
(10 × 8 inch) 8r-8f 1.3-1.5 MB 2048x1536 (3 million) 25.40 × 20.32

You can also calculate the correct digital photo output size based on the following formula.
Shooting resolution limit 300dpi = output size
For example, if the number of photos taken is 1.5 million pixels (1024x1536), divide 1024 and 1536 by 300 to get a 3.5 x (3R size ). That is to say, the maximum limit of printing a 1.5 million pixel digital photo is 3R, and so on.

Photo size table
1x1.5 inch: 2.5x3.5 (CM); 2.2X3.2 (CM); 3.3x4.8 (cm)
1.5x2 inch: two-inch 3.5x4.9 (CM); two-inch 3.5x4.5 (CM); two-inch 3.5x5.3 (cm)
1-inch 1R 2.6x3.7 (cm)
2-inch 2R 6.3x8.9 (cm)
5x3.5 (5 inch 3R) 12.70x8.89 (cm)
6 × 4 (6 inch 4R) 15.24 × 10.16 (cm)
7x5 (7 inch 5R) 17.78x12.70 (cm)
8 × 6 (8 inch 6R) 20.32 × 15.24 (cm)
10 × 8 (10 inch 8r) 25.40 × 20.32 (cm)
12 × 10 (12 inch) 30.48 × 25.40 (cm)
14 × 12 (14 inch) 35.56 × 30.48 (cm)
16 × 12 (16 inch) 40.64 × 30.48 (cm)
18 × 12 (18 inch) 45.72 × 30.48 (cm)
18 × 14 (18 inch) 45.72 × 35.56 (cm)
20 × 16 (20 inch) 50.80 × 40.64 (cm)
20 × 18 (20 inch) 50.80 × 45.72 (cm)
24 × 20 (24 inch) 60.96 × 50.80 (cm)
30 × 24 (30 inch) 76.20 × 60.96 (cm)
32 × 24 (32 inch) 81.28 × 60.96 (cm)
36 × 24 (36 inch) 91.44 × 60.96 (cm)
40x32 (40 inch) 101.6x81.28 (cm)
42 × 32 (42 inch) 106.6 × 81.28 (cm)
48 × 32 (48 Inch) 121.9 × 81.28 (cm)

(Note: for example, passports and visa applications, the level-1 certificate usually uses a large size, 48mm × 33mm. While the ID card, body check table, and so on mostly use small inch 32mm × 22mm, the second generation ID card (26mm × 32mm), ordinary inch is 25mm × 35mm. Standard Photo size for passport travel documents: 48mm × 33mm, 21mm mm to mm ~ 24mm, with a head length of 28mm ~ 33mm .)

Size table of various certificates
1. ID card (22mm × 32mm) Second Generation ID card (26mm × 32mm)
2. Driver's license (22mm × 32mm)
3. Black and white small inch (22mm × 32mm)
4. Small color inch (27mm × 38mm)
5. Large-inch color (40mm × 55mm)
6. General certificate Photo (33mm × 48mm)
7.1 inch (25mm × 35mm)
8.2 inch (35mm × 49mm)
9.3 inch (35mm × 52mm)
10. Hong Kong and Macao pass (33mm × 48mm)
11. U.S. Visa (50mm × 50mm)
12. Japanese Visa (45mm × 45mm)
13. Large two-inch (35mm × 45mm)
14. Passport (33mm × 48mm)
15. graduation photos (33mm × 48mm)
16. Driver's license (21mm × 26mm)
17. Car photos (60mm × 91mm)

Generally, the optimal printing effect of digital printing requires at least 160 dpi resolution of the original data file; 120 DPI is required for better results; or at least DPI for the bottom line. When it goes down, there will be obvious sertices (lines) and interpolation blur.