Metric Cross Stitch

I ordered 3 very cute cross stitch kits from a company named Riolis, through the stitchery.  They were made in Lithuania.  I really enjoyed working on the kits. They were on 10 count Zweigart Aida fabric done with a wool and acrylic yarn.  So they filled in really nicely. I went to order frames and found the cross stitch was 20 by 20 cm, except in English measurements that is 7.75 by 7.75.  I ordered 8 inch frames but now I need to put one row of stitching all around the picture so they fit.