A quilt block may be made any size you wish. There are different ways to enlarge a quilt block. I will explain them in the following paragraphs.
The simplest way to find a larger block is to look in other books that might have larger block patterns already available. A larger block could be available either as templates or with rotary cutting directions. There are many books available with just basic blocks and many free block patterns are available online.
Making photo copy enlargements of quilting templates is not recommended. Standard photo copy machines have a small percentage of distortion when making a direct 100% copy. This would cause your templates to 'stretch' either vertically or horizontally. When you are enlarging or reducing templates there is additional distortion. Any distortion in the templates would cause inaccurate piecing problems. If you are enlarging or reducing appliqué patterns or quilting designs the small amount of distortion is not noticeable.
The best way to enlarge a block pattern is to draft it yourself. This is not difficult. Look at your block and discover if it is a 9-patch, 4-patch, or another design grid. Once you are aware of the design grid it is fairly simple to draft a larger block.
Some blocks don't need to be re-drafted. You simply need to do a little math. This is easy. If you wish you can use a small hand held calculator but most of the time the calculations are very simple.
Let's take a 9-patch as an example.
Your basic block is a 6" finished simple 9-patch. Your nine individual squares finish at 2" and are cut 2 1/2" to include seam allowance.
You would like your block to be a 7 1/2" finished block. Your nine individual squares finish at 2 1/2" and are cut 3" to include seam allowance.
You would like your block to be a 9" finished block. Your nine individual squares finish at 3" and are cut 3 1/2" to include seam allowance.
You would like your block to be a 12" finished block. Your nine individual squares finish at 4" and are cut 4 1/2" to include seam allowance.
You would like your block to be a 15" finished block. Your nine individual squares finish at 5" and are cut 5 1/2" to include seam allowance.
You would like your block to be a 18" finished block. Your nine individual squares finish at 6" and are cut 6 1/2" to include seam allowance.
You would like your block to be a 24" finished block. Your nine individual squares finish at 8" and are cut 8 1/2" to include seam allowance.
As you see you can continue on and not really have to draft for a simple block. A more intricate pattern would need to be drafted. Drafting is not difficult. Sometimes you don't have to draft the entire block. Just look at the configuration of your block. Some of the sections are just plain squares, half-square, or quarter-square triangles.
It is easier to say and understand the divisor is 3. If you look at your numbers, all are divisible by 3 and each add an 1 1/2" seam allowance when completed; e.g. 9,3 and 3 1/2.
Remember for squares measure the finished size and add 1/2" for seam allowance. For half square triangles measure the finished size and add 7/8" for seam allowance. For quarter-square triangles, measure the finished size and add 1 1/4" for seam allowance. Occasionally you would have to draft only a very intricate portion of your block.
To draft a quilt block, all you need is an accurate ruler - I like the C-line brand available at office supply stores. They are clear with a red grid like graph paper. You'll also need a sharp pencil - a mechanical pencil is nice - and a large sheet of plain paper or graph paper. Graph paper would be used if you are making your pattern a nice even number like a nine-patch or four-patch. Plain paper would be preferable if you are drafting a more intricate pattern such as an eight-pointed star or a block with fractions in the finished size.
Please do not feel intimidated by this. Most quilt block drafting is simple elementary school math. We learned it when we were in school and just haven't had a place to apply it since then. When you get started, you will find your memory will remember this skill of simple addition, subtraction, multiplication and division.
Drafting is a skill that is very difficult to describe in a simple newsletter so I am going to recommend you reference a good basic quilt book. Most basic quilt books have a chapter discussing drafting quilt block patterns and you might have some in your personal library or can check your local library. You might also check online for quilt block drafting instructions.