how many blocks?
 

I have 6 inch blocks and want to make a twin size quilt, how many blocks do I need. Is there a formula to figure this out? Also what size is a twin size quilt? I've seen many different measurements.

Size is up to you. I like my twins to be around 60x90, but that is bigger than most people make them. So if your blocks are 6” Uunfinished than that is 5.5” finished in the quilt. 60 divided by 5.5 is 10.9 so you could do 10 or 11 wide. Then 90 divided by 5.5 is 16.36, so I would do it 10 blocks wide by 16 blocks long, so 160 blocks. That all changes if you want sashing, or on point setting, or many other factors. But a straight side by side block set would be 160 blocks.

Also, there are 2 types of twin mattresses. I think both are the same width, but one is longer. When my niece was purchasing for her dorm room, the info stated that she needed Long Twin sheets.

There are several sites that suggest how to measure for bedding.

If you do a search for "quilt size" - many things come up.

Some factors:

Mattress size
Mattress depth
How much overhang
A pillow-tuck or not
The pattern you want to use
How much fabric you have

Adding to list
* bedskirt or not?
* borders or not around the blocks? (OP asked for # blocks)

* and no doubt there are more to be added ...........

As to figuring out "how many blocks do I need"

The first thing I would do would be to decide on an approximate finished size.

Then go by the "finished" size of the blocks/units I intend to use.

I "think" either with graph paper or by laying blocks out on something - a bed, the floor, or a design wall. (A design wall is preferable, but one does what one can with what one has.)

After I get a layout/overall design I think I like, then I start to do the serious calculating.

Sometimes it's with a ruler or tape measure - sometimes it's "calculating" on graph paper -

Now that I've written this, it seems that I have sort of a "however/whatever" approach.

As indicated in previous responses, the correct answer to how many 6" blocks are needed to make a twin size quilt is--a LOT! There are too many variables in giving an absolute answer. Straight set or on point? Do you want to put these blocks only on the top of the mattress and border out the overhang? If you want to include them in the overhang, how deep is the overhang? Do you want to cover the pillows or not? But with only a 6'' block, it is going to take a lot of blocks whatever your intent.

The question of sizes comes up often. You can make it whatever size you want. Google sizes and that is a starting point. But, depending on the finished size of your blocks, sashing or none, what size borders and how many, and (I think most important) the design layout of the blocks will determine how big your finished quilt should be. We all promise that there aren't any quilt police going to come to your home and measure your quilt - have fun and just be creative!

I thought this was going to be easy, was I wrong. I flunked geometry, so guess I will limp along. thanks for your help.

A lot depends on the specific bed...The full sized mattress my mother just bought is so deep that queen size quilts barely cover it. I had to add extra rows onto the quilt I just made her!