Below is the chart with the most common sizes from inches to centimetres.Standard photo sizes in inchesPhoto size in centimetresSimilar metric size6×4″15.24 x 10.16 cm15 x 10 cm7×5″17.78 x 12.7 cm18 x 13 cm10×8″25.4 x 20.32 cm25 x 20 cm12×8″30.48 x 20.32 cm30 x 20 cm