Quilt Size Chart: Pick the Size Before You Cut

The worst moment to discover a quilt is the wrong size is when it is finished.

You lay it on the bed, one side hangs eight inches lower than the other, and the border you spent a weekend on disappears under the mattress. Most of the time the problem is not the sewing. It is that nobody wrote down the two measurements the quilt actually needed, which is what a quilt size chart is for, and why a chart on its own is not quite enough.

Karen Brown of Just Get it Done Quilts works through the whole decision in the video below. The arithmetic goes past quickly on screen, so the numbers and the formula are written out underneath.

Every quilt size chart starts with the mattress

A quilt has no standard size. A mattress does. Everything else is a decision you make on top of that.

Karen makes a point worth repeating before any chart: in researching her video she found no fewer than 36 commercially available mattress sizes. Ten of them are kings. The largest she found, the Alaskan king, is 108 inches square. There are separate standards for the United States, the United Kingdom and Europe, and there are sizes built for recreational vehicles, pickups and water beds.

So the first job is not to look up a chart. It is to measure the actual bed.

That said, most beds in the United States are one of six sizes.

Two notes on that table, because the difference matters when you are cutting fabric.

The crib figure is not a convention, it is law. A full size crib mattress sold in the United States has to be at least 27 1/4 inches wide and 51 5/8 inches long, under 16 CFR 1241.2. It is the only row here with a legal floor under it.

The full is the one row where sources disagree. Some list it at 53 inches wide and some at 54. If you are making a full sized quilt, measure the bed rather than trusting either of us. One inch is a rounding error in a bedroom and a visible problem at the edge of a quilt.

The part a quilt size chart leaves out: your drape

Here is the gap in every chart, including the one above. A mattress is 60 by 80. A quilt for that mattress is not.

How much bigger depends on how far you want the quilt to hang down, and that is a decision, not a measurement. Karen lists four honest answers. The quilt can sit on top of the mattress, drop down over the sides, tuck in, or hang to the floor like a bedspread. She is blunt about the right way to choose: ask the person you are making it for.

Once you know the drape you want, the arithmetic is short.

Finished width = mattress width + (2 x drape). The quilt hangs down on both sides, so the drape counts twice.

Finished length = mattress length + (1 x drape). Only once, because pillows normally sit on top of the quilt rather than under it, so nothing is added at the head end. Karen's figure for that pillow zone is about 20 inches. If the person you are sewing for wants the quilt to cover the pillows, add the drape at the top as well, and ask before you assume.

To turn the drape into a number, start with the thickness of the mattress. Karen points out how wide that range is: from a four inch foam mattress to a coil mattress with a topper at ten inches or more. A quilt that just covers the sides needs a drape roughly equal to that thickness. Anything beyond it is preference.

The table below applies the formula to the six standard mattresses at two example drapes. Eight and twelve inches are not standards. They are worked examples chosen to bracket the mattress thicknesses Karen describes, so you can see how fast the numbers move.

Look at the king row. Four extra inches of drape adds eight inches of width. That is another row of blocks, another border, and a different backing.

Map it out before you cut anything

There is a second problem that no chart can solve, and Karen puts it better than most.

We judge a quilt flat, looking straight down at it. It gets used draped over a rectangle. Those are not the same shape, and the consequence is that the centre of your quilt often does not land on the centre of the mattress. The edges of the bed then cut through the design, and the medallion you built the whole quilt around ends up half over the side.

Her fix costs ten minutes. Draw the mattress. Add the drape. Mark the twenty inches the pillows will cover. Mark where you want the centre of the design to fall. Then draw your pattern's finished measurements over the top and see what actually lines up. Graph paper, a sketch, or a screen all work.

If the pattern comes out one to four inches larger than the size you wanted, Karen's advice is to do nothing at all. That is inside the margin where nobody will ever notice. Beyond that, you have three levers.

Three ways to resize a quilt top before it is quilted

All three work in both directions. To shrink a quilt, do the opposite of each.

Add a border

The most obvious lever and the most flexible one. Borders do not have to be the same width on every side, and they do not have to go on all four sides. A wider border at the foot and narrower ones elsewhere is a legitimate design choice, not a compromise.

Worth thinking about carefully, because the edges of the quilt are what you see first when you walk into a bedroom.

Extend the block design

Instead of framing the quilt, carry it outward. Half blocks or quarter blocks around the edge grow the top while keeping the design continuous. This is the lever that changes the look least, since there is nothing new to look at, just more of what was already there.

Widen the sashing

The quiet one, and the one people forget. Sashing runs between every block, so a small change repeats many times. Karen's example: an extra half inch of sashing across eight rows adds four inches to the quilt.

You can also add sashing to a pattern that has none, but be clear with yourself that this changes the design rather than just the dimensions. If you have not used it before, sashing between scrappy blocks is a gentle place to start.

If you would rather solve the problem without a border at all, a modern quilt without borders takes the opposite approach, and borders, backing and binding for any quilt top covers how the three decisions interact.

What to do when the quilt is already quilted

Harder, but not lost. And Karen's framing is the right one: a quilt that gets used is worth more than a perfect quilt in a cupboard.

To make a quilted quilt bigger, she adds to the edge using a quilt as you go method. Remove the binding. Sew the additional quilt top and backing to the edge. Join a strip of batting to the existing batting with a zigzag or a running stitch. Fold the new top and backing back over that batting, secure with pins or adhesive, quilt as desired, then put the binding back on.

One condition that is easy to miss. If the quilt has already been washed, use pre-washed fabrics for the addition and pre-wash the batting too. Otherwise the new section shrinks and the old one does not.

If quilt as you go is new to you, our beginner's guide to the quilt as you go technique is by the same maker and covers the method properly before you try it on a finished quilt.

When the quilt came out too big

Try washing it first, and this is where the numbers get useful.

Karen's figures, from her own testing on shrinkage: unwashed fabrics and batting can shrink up to 12 percent, and pre-washed fabrics a further 2 percent. On a large quilt that alone may be the whole fix.

She made a bedspread sized quilt that was long enough to cover the drawers in the bed base, and the household kept tripping on it. She took it to a laundromat, found the biggest machine there, and it came out five inches smaller in both directions.

If washing is not enough, the last resort is to remove the binding, trim equally from opposite edges so the design stays centred, and rebind. Cutting off finished work is painful. A quilt nobody uses is worse.

The sizes we actually cut

Here is a number no chart will give you, because it comes from our cutting table rather than from a bed.

Our precut quilt kits carry their finished measurement in the title. They sit between 58 and 68 inches wide, and between 62 and 90 inches long. That is not an accident. It is the range that covers a twin bed properly, a queen or king as a top-of-mattress throw, and a sofa, which is where most finished quilts actually end up.

Two of them, Heartland Home and Peppermint Poinsettias, come with an 84 by 96 option as well, which takes the same design up to full and queen with a real drape.

If you are choosing a first project rather than sizing one you have already designed, our beginner quilt patterns are grouped so you can see the finished size before you commit.

Batting and backing have sizes of their own

The quilt top is only the first of three layers, and the other two come in fixed widths. Working out the quilt size and only then discovering the batting does not cover it is a common and avoidable annoyance.

Our cotton and polyester batting comes in three cuts: twin at 72 by 90, full at 81 by 96, and queen at 90 by 108. Compare those against the table above before you settle on a drape. A queen mattress with a twelve inch drape needs an 84 by 92 quilt, which fits inside the queen batting with room to spare, and does not fit the full.

Backing is the other constraint, and it is the one that decides whether you have to piece. A 108 inch wide backing in a three yard cut gives you a piece 108 inches square, which backs a quilt up to about 100 inches in each direction with a four inch overhang all round. Above that, or on a narrower fabric, you are piecing the back, and piecing a quilt backing walks through the seams. There is also a quicker way to work out the backing size once you know your finished measurement.

Questions people ask about quilt sizes

What are the standard quilt sizes? There are none. Mattresses have standard sizes. A quilt size is the mattress plus the drape you choose, which is why two people can make a correctly sized queen quilt eight inches apart.

What size quilt is 60 by 80? That is a queen mattress exactly, so a 60 by 80 quilt sits on top of a queen with no overhang at all. On a twin, 60 by 80 gives roughly eleven inches of drape each side.

How much bigger than the mattress should a quilt be? Twice your drape on the width, one drape on the length, nothing at the top if pillows will sit on the quilt. Start the drape at the thickness of the mattress, which runs from about four inches to over ten.

My pattern is three inches out. Do I fix it? No. Under four inches, leave it.

Can I still change the size after quilting? Bigger, yes, by adding to the edge with quilt as you go. Smaller, yes, by washing it or by trimming and rebinding.

Before you cut

Two measurements and one question, and they take about a minute between them.

The width and length of the actual mattress, not the name of it. And the question that decides everything else: how far down do you want this to hang.

Karen keeps a downloadable chart of mattress sizes and matching quilt sizes at several drapes on her quilt sizes page, which is worth having beside the machine if you make a lot of bed quilts.

A last thought

There is something quietly generous about measuring someone's bed before you make them a quilt.

It means you thought about where it would live. That it would be pulled up on a cold night by a particular person, in a particular room, and that you wanted it to reach.

Nobody who receives a quilt knows about the drape arithmetic. They only know it fits.

Marbelia Fernandes
The Fabric Hut Co-Founder

P.S. If you only remember one number from all of this, remember twenty. That is roughly how much of the top of your quilt disappears under the pillows, and it is the reason a quilt that measures perfectly can still look short on the bed.