I agree with Geri B. Keep your seam allowance at 1/4 inch and it should fit perfect. If it is too tight add a small border around your block. This will also help if your seams are not kept at 1/4 inch. Can I also suggest you add a backing to the pieces top if you plan to remove the insert for washing. This will keep your fabric from fraying. Enjoy your hobby and show us pictures when you are done