How to Make the Ohio Star Quilt Block: Pattern and Measurements

Five plain squares and four hourglasses.

That is the whole Ohio Star quilt block. It is a nine-patch, three rows of three, and the four units along the sides are the star. Once you see the block that way it stops being a star you have to draw and becomes nine things you have to cut, which is a far easier problem.

What follows is the complete block. What it is made of, what to cut for five different sizes, how to make the star point units so the points survive being sewn, and how to turn one block into a quilt. There is a free pattern sheet at the end, and you do not have to hand over an email address to get it.

What the Ohio Star quilt block is

Nine units in a three by three grid. Five of them are plain squares, four corners and one center. The other four are quarter square triangle units, one on each side, and those four are the star.

A quarter square triangle unit is a square divided by both diagonals into four triangles. Quilters also call it an hourglass unit, because two of the four triangles usually match and read as an hourglass across the middle. In the Ohio Star that hourglass always points at the center square. Get that orientation right and the four separate units read as one star. Get one of them turned and the star falls apart, which is the only mistake this block really punishes at the layout stage.

Because the grid is three by three, the math is simple. A 12 inch block is nine 4 inch units. A 9 inch block is nine 3 inch units. Anything that divides by three works, which is why this block can be made in almost any size without a template.

It is worth knowing the star quilt block next door. A Sawtooth Star has the same nine-patch layout but uses flying geese units for the points, so each point is a single triangle aimed outward. The Ohio Star uses quarter square triangles, so each point has a triangle aimed out and another aimed in. That is why an Ohio Star looks slimmer and slightly turned, and why the two blocks are so often confused in photographs.

What to cut, in five block sizes

The fabric requirements are small. Two fabrics for the classic quilt block, one light and one dark, and a third if you want the center square to read on its own.

The cutting instructions read like this. A is the five plain squares, four corners and one center. B is the four squares the star point units get cut from, two light and two dark. Every number below is in inches, and you trim each finished star point unit to the same size as the A squares.

The formula behind the table is worth more than the table. Take the unit size, add 1/2 inch for the plain squares and 1 1/4 inches for the star point squares. That is it. Any block size that divides by three can be worked out on the back of an envelope.

The 8 inch block is the exception, because 8 does not divide into three whole inches. Those two numbers come from Barbara Brackman's Civil War Sampler, where the Ohio Star is block 19, and they run very slightly small on purpose. She asks for a scant 1/4 inch seam through the whole block to make up the difference.

Cutting from precuts and yardage

The 12 inch block and a layer cake get along well. One 10 inch square gives you a 5 1/4 inch square for the star points and a 4 1/2 inch square for a corner, with fabric left over.

A charm pack is a different story. A 5 inch charm has everything the 9 inch block needs, since the largest piece there is 4 1/4 inches. It cannot make the 12 inch block, because that one wants 5 1/4 inch squares and a charm square is a quarter inch short.

Precuts suit the star points, where every block can happily take a different fabric. The background is the opposite case. It repeats in every block of the quilt, and it is what the points are read against, so it wants to come off one bolt from the first block to the last. That is a job for fabric by the yard rather than for a bundle, and solids are what keep the star points crisp.

Fat quarters sit between the two. They are the practical cut for a scrappy set where every block gets its own star and no fabric has to stretch across the whole quilt.

Making the four star point units

You can cut quarter square triangles directly, by cutting a square in half diagonally twice. The faster and more forgiving route starts with whole squares and never touches a bias edge until the seam is already sewn.

Take two light and two dark squares at the B size. Pair one light with one dark, right sides together, draw a diagonal line on the wrong side of the light square, and sew 1/4 inch either side of that drawn line. Cut on the line and press towards the darker fabric, and you have two half square triangle units. Repeat with the other pair and you have four.

The whole unit, in three methods with a printable size chart, is in our guide to making quarter square triangles. That first step is the standard two at a time half square triangle method, and it is the one place this block borrows from another. If half square triangles are new, or if you want the faster ways of making a lot of them, our guide to making half square triangles has all three methods and a printable size chart.

Now pair two of those units, right sides together, with the diagonal seams running in opposite directions so they nest, and the light triangle of one sitting against the dark of the other. Draw the other diagonal line, sew 1/4 inch either side, cut on the line and press. Two quarter square triangle units. Do it again with the remaining pair and the block has all four star points.

Trim every unit to the size of the A squares. This is the step people skip and it is the one that decides whether the rows line up later. Squaring up a finished block does not rescue units that were never square, it just cuts the star points off.

Sewing the block together

Lay out the nine units before you sew anything. Row one is corner, star point, corner. Row two is star point, center, star point. Row three repeats row one. Check that every hourglass is pointing at the center square.

Sew each row with a 1/4 inch seam. Press seams in rows one and three toward the corner squares, and press seams in row two toward the center. The seams then lie in opposite directions where the rows meet, so they nest against each other and the intersections sit flat without being forced.

Join the rows last. Pin through the exact point where the two seams cross, on both layers, and stitch so the needle passes through that point. Press the two long seams in the same direction.

Measure the block. It should come off the machine at the finished size plus 1/2 inch, so a 12 inch Ohio Star measures 12 1/2 inches square before it goes anywhere near a quilt top.

Why star points get cut off, and how to stop it

The tip of each star point sits exactly 1/4 inch in from the raw edge. There is no margin in that number. A seam allowance a thread too wide eats the point, and a block with eight points gives the error eight chances to show.

Three habits fix almost all of it.

Trim the units to size before assembly, not the block afterwards. A quarter square triangle unit that finishes an eighth of an inch small has nowhere to hide between two that did not.

Pin through the seam intersection itself, through both layers, rather than beside it. The pin holds the point where it needs to be while the feed dogs try to move it.

And keep one seam allowance for the whole block. A consistent scant 1/4 inch beats an inconsistent exact one every time, because the block only needs the nine units to agree with each other. Something that sets a physical stop on the machine bed helps here more than a marked line does. Our seam guide ruler bundle does that at any allowance from an eighth of an inch to two inches, and it comes with forty 2.5 by 10 inch strips, which is enough fabric to make your first few blocks without cutting into anything you were saving.

A square ruler in your unit size is the other thing worth owning, because trimming four units in four single cuts is a different job from trimming them in eight.

Look at the blade before you start a stack of units, too. A blade that has gone dull stops slicing and starts dragging, and the layers shift a fraction under the ruler without you feeling it happen. On a block where a thirty second of an inch decides whether a point survives, that is not a small thing. A fresh rotary blade costs less than the fabric you lose recutting units that were never square.

Choosing the fabrics

The Ohio Star is a contrast block before it is a colour block. What decides whether the star appears is value, which is how light or dark a fabric is rather than what colour it is. A mixture of light, medium and dark is what gives a block like this its structure, and a set of fabrics that all sit at the same value will read as a flat square from across the room no matter how pretty they are up close.

The simplest version uses two fabrics. A light background fabric for the corners and the outer halves of the star point units, and a dark for the star. The center square then goes one of two ways. Keep it the same dark as the points and the star reads as one solid shape. Give it a third fabric and the block gains a middle, which is what most of the antique versions do.

Colour does the rest. A scrappy set built from scraps and fat quarters, with a different star in every block, a two colour set that repeats across the quilt, or a single star made very large as a whole cot quilt. The geometry never moves, so all of them work.

Turning the block into a quilt

The math is friendly. Twenty 12 inch quilt blocks set four across and five down give an Ohio Star quilt top of 48 by 60 inches, which is a good throw before any border. Thirty blocks set five by six give 60 by 72 inches. Nine 12 inch blocks make a 36 inch square baby quilt or a wall hanging.

If twenty Ohio Stars sounds like a lot of quarter square triangles, a star quilt does not have to be all stars. Use an alternating setting and put a plain block between them. Half the piecing, and the stars get room to be looked at. Sashing does the same job and adds an inch or two of finished size for every strip you put in.

The free Ohio Star pattern sheet

Everything above fits on two pages, and we have put it there so you can keep it next to the machine instead of scrolling on a phone with pins in your hand.

The sheet has the block diagram, the cutting table for all five sizes, a diagram of the star point method step by step, and the assembly and pressing instructions. It prints on letter or A4 and nothing on it needs to print at actual size, because this block has no templates.

The download is here: the Ohio Star quilt block pattern sheet. It is free to print, use and teach.

Ohio Star questions we are asked most

What size squares do I need for a 12 inch Ohio Star block?

Five squares at 4 1/2 inches for the corners and center, and four squares at 5 1/4 inches, two light and two dark, for the star points. Trim each finished star point unit to 4 1/2 inches before you assemble the block.

What is the difference between a Sawtooth Star and an Ohio Star?

The layout is the same nine-patch. The units are not. A Sawtooth Star uses flying geese for the four side units, so each point is one triangle aimed outward. An Ohio Star uses quarter square triangle units, so each point has a triangle aimed out and one aimed in. The Ohio Star looks slimmer and slightly rotated as a result.

Is there a free printable Ohio Star pattern?

There is one at the top of this section, and it costs nothing. What it will not contain is templates to cut around, because there are none in this block. Every piece is a square cut with a rotary cutter, so what you actually need is the cutting table, and that prints at any scale you like.

Is the Ohio Star good for a beginner?

It is a good second or third block rather than a first one. Nothing in it is difficult on its own, and there are no curves, no set in seams and no templates. What it does ask for is an accurate seam allowance, and it tells you immediately when you do not have one.

A better first block is a four-patch or a nine-patch of plain squares. Straight seams, no triangles, and the only thing being tested is whether your quarter inch stays the same from one seam to the next, which is the skill everything else sits on. Our complete beginner guide to making a quilt starts there and carries on to binding.

The step between that block and this one is the half square triangle, and it is worth taking on its own, because the star point unit here is two half square triangles sewn together a second time. Learn those first in how to make half square triangles, and the Ohio Star stops being a new technique and becomes a new arrangement of one you already have. The block to make in between is the Friendship Star. Same nine-patch, same five plain squares, but the four side units are half square triangles instead of hourglasses, so it is this block with the hard part taken out.

Why do my star points get cut off?

Almost always the seam allowance, and almost always at the row joining stage rather than in the units. The point sits 1/4 inch from the raw edge, so a slightly wide seam removes it. Trim the units to size before assembly, pin through the intersection, and check one block against the table before you cut fabric for nineteen more.

Can I make it from a charm pack?

Yes for the 9 inch block, where the largest piece is 4 1/4 inches. No for the 12 inch block, which needs 5 1/4 inch squares. A layer cake covers both.

Where does the name come from?

The block is an old nine-patch star that has carried several names in print over the years, and the Ohio Star name is the one that stuck. Barbara Brackman includes it under that name in her Civil War Sampler, where she ties it to Oberlin, Ohio. Anyone telling you a precise date of origin for a block this common is guessing.

What to have ready

• A light and a dark quilting cotton, and a third fabric if the center square is getting its own. Solids are what keep the star points crisp.
• A rotary cutter with a sharp blade, a mat, and a square ruler in your unit size for trimming.
• Something that keeps the 1/4 inch honest on every seam. Our seam guide ruler sets a physical stop on the machine bed and comes with forty strips to practise on.
• A marking pen or pencil, pins and clips, all of which live in notions.
• An iron, and the patience to press rather than push.
• The pattern sheet above, printed.

Where to start

Make one Ohio Star quilt block at 12 inches before you decide anything about a quilt. Cut five squares at 4 1/2 inches and four at 5 1/4 inches, build the four star point units, trim them, and sew the three rows.

Then measure it. If it is 12 1/2 inches square, the seam allowance is right and every other size in the table will behave. If it is not, you have learned that on one block instead of on twenty.

Marbelia Fernandes
The Fabric Hut Co-Founder

P.S. Keep the first Ohio Star you make, points cut off and all. It is the fastest way to see how much your quarter inch has improved a year from now.