<P> Unlike ISO 216 paper sizes, the aspect ratios of photographic prints vary, so exact scaling of prints is not always possible . However, there are some logical correspondences between the sizes, noted below when applicable . </P> <P> Many of the standard sizes are the same as sheet film formats, and are appropriate for making contact sheets from these films . </P> <Table> <Tr> <Th> US code </Th> <Th> Japan code </Th> <Th> Alias </Th> <Th> Size inches (mm) </Th> <Th> Pixels at 300 PPI </Th> <Th> Aspect ratio </Th> <Th> Notes </Th> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td> Wallet </Td> <Td> 2 × 3 (51 × 76) </Td> <Td> 600 × 900 </Td> <Td> 3: 2 (1.5) </Td> <Td> Very often called "wallet" size . </Td> </Tr> <Tr> <Td> 2R </Td> <Td> </Td> <Td> Wallet </Td> <Td> ​ 2 ⁄ × ​ 3 ⁄ (63.5 × 89) </Td> <Td> 750 × 1050 </Td> <Td> 7: 5 (1.4) </Td> <Td> Older standard for "wallet" size . </Td> </Tr> <Tr> <Td> </Td> <Td> DSC </Td> <Td> </Td> <Td> ​ 3 ⁄ × ​ 4 ⁄ (83 × 119) </Td> <Td> 974 × 1417 </Td> <Td> 16: 11 (1.45) </Td> <Td> Size in inches is approximate . </Td> </Tr> <Tr> <Td> 3R </Td> <Td> </Td> <Td> 9 × 13 cm, B7, Enprint </Td> <Td> ​ 3 ⁄ × 5 (89 × 127) </Td> <Td> 1050 × 1500 </Td> <Td> 10: 7 (1.43) </Td> <Td> </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td> Chou #4 </Td> <Td> 3.5 × 8.1 (90 × 205) </Td> <Td> 1050 × 2430 </Td> <Td> 16: 7 (2.29) </Td> <Td> envelope size </Td> </Tr> <Tr> <Td> </Td> <Td> PC </Td> <Td> Hagaki, A6 </Td> <Td> 3.9 × 5.8 (100 × 148) </Td> <Td> 1170 × 1740 </Td> <Td> 3: 2 (1.5) </Td> <Td> postcard size </Td> </Tr> <Tr> <Td> 4R </Td> <Td> KG </Td> <Td> 10 × 15 cm </Td> <Td> 4 × 6 (102 × 152) </Td> <Td> 1200 × 1800 </Td> <Td> 3: 2 (1.5) </Td> <Td> standard 135 film & print size </Td> </Tr> <Tr> <Td> 4D, 6D </Td> <Td> </Td> <Td> </Td> <Td> ​ 4 ⁄ × 6 (114 × 152) </Td> <Td> 1350 × 1800 </Td> <Td> 4: 3 (1.33) </Td> <Td> new size for most consumer level digital cameras and Micro 4 / 3 cameras </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td> Chou #3 </Td> <Td> 4.7 × 9.3 (120 × 235) </Td> <Td> 1410 × 2790 </Td> <Td> 2: 1 (2.0) </Td> <Td> envelope size </Td> </Tr> <Tr> <Td> 5R </Td> <Td> 2L </Td> <Td> 13 × 18 cm, B6 </Td> <Td> 5 × 7 (127 × 178) </Td> <Td> 1500 × 2100 </Td> <Td> 7: 5 (1.4) </Td> <Td> twice the size of a 2R print </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td> Ofuku Hagaki, A5 </Td> <Td> 5.8 × 7.9 (148 × 200) </Td> <Td> 1740 × 2370 </Td> <Td> 4: 3 (1.33) </Td> <Td> postcard size </Td> </Tr> <Tr> <Td> 6R </Td> <Td> 8P </Td> <Td> 15 × 20 cm </Td> <Td> 6 × 8 (152 × 203) </Td> <Td> 1800 × 2400 </Td> <Td> 4: 3 (1.33) </Td> <Td> twice the size of a 4R print </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td> 18 × 24 cm </Td> <Td> 7 × ​ 9 ⁄ (178 × 240) </Td> <Td> 2100 × 2850 </Td> <Td> 19: 14 (1.36) </Td> <Td> for B&W paper </Td> </Tr> <Tr> <Td> 8R </Td> <Td> 6P </Td> <Td> 20 × 25 cm </Td> <Td> 8 × 10 (203 × 254) </Td> <Td> 2400 × 3000 </Td> <Td> 5: 4 (1.25) </Td> <Td> Can be used for contact prints from 8 × 10 film . </Td> </Tr> <Tr> <Td> S8R </Td> <Td> 6PW </Td> <Td> 20 × 30 cm </Td> <Td> 8 × 12 (203 × 305) </Td> <Td> 2400 × 3600 </Td> <Td> 3: 2 (1.5) </Td> <Td> closest approximation to A4 (210 × 297mm), twice the size of a 6R print </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td> 24 × 30 cm </Td> <Td> ​ 9 ⁄ × 12 (240 × 305) </Td> <Td> 2850 × 3600 </Td> <Td> 24: 19 (1.26) </Td> <Td> for B&W paper </Td> </Tr> <Tr> <Td> 10R </Td> <Td> 4P </Td> <Td> </Td> <Td> 10 × 12 (254 × 305) </Td> <Td> 3000 × 3600 </Td> <Td> 6: 5 (1.2) </Td> <Td> </Td> </Tr> <Tr> <Td> S10R </Td> <Td> 4PW </Td> <Td> </Td> <Td> 10 × 15 (254 × 381) </Td> <Td> 3000 × 4500 </Td> <Td> 3: 2 (1.5) </Td> <Td> At 141⁄2 in (368 mm), the Japanese 4PW size is slightly shorter than S10R . </Td> </Tr> <Tr> <Td> 11R </Td> <Td> </Td> <Td> 28 × 36 cm </Td> <Td> 11 × 14 (279 × 356) </Td> <Td> 3300 × 4200 </Td> <Td> 14: 11 (1.27) </Td> <Td> </Td> </Tr> <Tr> <Td> S11R </Td> <Td> </Td> <Td> </Td> <Td> 11 × 17 (279 × 432) </Td> <Td> 3300 × 5100 </Td> <Td> 17: 11 (1.55) </Td> <Td> </Td> </Tr> <Tr> <Td> 12R </Td> <Td> </Td> <Td> </Td> <Td> 12 × 15 (305 × 381) </Td> <Td> 3600 × 4500 </Td> <Td> 5: 4 (1.25) </Td> <Td> </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td> 30 × 40 cm </Td> <Td> 12 × 16 (305 × 406) </Td> <Td> 3600 × 4800 </Td> <Td> 4: 3 (1.33) </Td> <Td> for B&W paper </Td> </Tr> <Tr> <Td> S12R </Td> <Td> </Td> <Td> </Td> <Td> 12 × 18 (305 × 457) </Td> <Td> 3600 × 5400 </Td> <Td> 3: 2 (1.5) </Td> <Td> </Td> </Tr> </Table> <Tr> <Th> US code </Th> <Th> Japan code </Th> <Th> Alias </Th> <Th> Size inches (mm) </Th> <Th> Pixels at 300 PPI </Th> <Th> Aspect ratio </Th> <Th> Notes </Th> </Tr>

What is the size of 4r photo in cm