If you are not sure which size is suitable for your laptop,you can check the size information or contact us with your laptop size information —-> L * W * H (Length * Width * Height).We are glad to help you find a suitable bag.size:11inch=21*2*28cm (L * W * H)13-13.3inch=34*2*26cm (L *W * H)14inch=37*3*28cm (L * W * H)15-15.6inch=39*3*29cm (L * W * H)16inch=40*3*30cm (L * W * H)