So, these are precut charm squares 5", and will finish at 4.5"?
Queen size is a rough concept, somewhere around 90x108".
The real math for determining a diagonal measurement of a square is 1.41 * side. For rough purposes (like determining yardage) round up to 1.5.
4.5 will be something yucky like 6.345... so 13 blocks across = 82, 14 = 88 . Keep in mind when you are on point you have the inner rows, so you will then also have 12 rows of those across. How many down depends on if you want a square or a rectangle.
You can use something like this for your setting and corner triangles:
http://www.quiltersparadiseesc.com/C...Calculator.php