Buying a photo frame but not sure what size you need for the photos you have printed?  Check out this handy Conversion Chart below ...

Frame Opening    Photo Size    
4 x 6 inches 10 x 15 cm
5 x 7 inches 13 x 18 cm
6 x 8 inches 15 x 20 cm
8 x 10 inches 25 x 20 cm
10 x 13 inches 25 x 33 cm
11 x 14 inches 28 x 35.54 cm
12 x 18 inches 30.5 x 46 cm
A4 21 x 29.7 cm
A3 29.7 x 42 cm
A2 42 x 59.4 cm