My 1/4 inch foot with a guide is a wide 1/4 inch so my blocks are always smaller also. As long as there is consistency and all seams are large, it hasn't been a problem I sometimes even add an extra row of the block to the top and bottom of the quilts, to make the quilt larger. The only problem I have had with it is when sewing a swatch block for a friend who needs an exact block size. Then for her block, I measure an scant 1/4 and mark my sewing bed with a piece of masking tape and sew slow.