The amount of blocks needed for a quilt of a certain size will be determined by the actual size of the block. This post covers quantities for the 12.5” blocks we’re creating in our youtube series, but a little jiggling around with the numbers and you’ll be able to figure out other sizes too.
Firstly, determine what size quilt you want to make. This will be different depending on where you are in the world. We’re in the UK, but the sizes are different for those of you in the USA.
Of course, there is no hard rule on the size you make a quilt. As long as it’s big enough for it’s purpose, it doesn’t matter what size it is. The measurements in this post are simply for those times where a certain size of quilt is required.
The blocks we’re making are 12.5 inches when finished, half an inch of that is allocated for seam allowance when combining blocks to form the quilt. So we use 12 inch as the final measurement. Let’s say we’re making a superking sized quilt (102×87 inches) from these 12 inch blocks. We divide the width (102”) by the size of the block (12”) – We end up with 8.5 blocks wide. Obviously some quilts just wont work with half blocks, so we round that up to 9. When you need to round, always round UP. The quilt needs to be 9 blocks wide.
Repeat this for the length: 87 / 12 = 7.25 (Round to 8).
So now you have the width and length you multiply the two, we need 9 columns and 8 rows.
9 x 8 = 72
It all boils down to maths. But when you’re calculating, be sure to use one measurement type only! Don’t mix inches and centimetres or you’ll get completely bamboozled! Here’s a quick image that you can save to your computer for future reference!