Oasis Poster Concert Then Forum October 17. This concert poster is approximately 20 inches by 29 inches. It is not in mint condition. There are slight corner dings. It is signed by the visual artist & numbered 240 out of 500. Conversion Table: Inches to Centimeters. 12 x 12 inches is approximately 30 x 30cm. 11 x 17 inches is approximately 28 x 43cm. 12 x 18 inches is approximately 31 x 46cm. 18 x 24 inches is approximately 46 x 61cm. 20 x 30 inches is approximately 51 x 76cm. 24 x 36 inches is approximately 61 x 91cm. For other dimensions please use the following conversion rate: 1 inch is equal to 2.54 centimeters, and 1 centimeter is equal to. If you have any difficulties with calculating dimensions, please let us know. The math-geniuses at Postersultan will be happy to help you out! Or at least we can try. If you would like to know more about us, our business or our products please check out our about me page. ATLEAST 1 OUT OF 10 ITEMS NEVER REACHES ITS DESTINATION. They are more clearly stated in our about me page. You can see them by clicking on the word ME next to our username POSTERSULTAN. Powered by SixBit’s eCommerce Solution.