Turn Flat Into Fitted Sheets - Craftsy

Fitted sheets can be pricier than flat ones and, depending on the material you want and the place you're shopping, they can even cost more than double. What's worse: sometimes fitted sheets aren't even included in bedding sets, and they can be hard to find in luxury natural fibers like durable cotton wovens or linen and hemp blends.

The solution? Make your own fitted sheets from the flat ones you already have on hand. Here's how.

DIY Fitted Sheets

Level: Intermediate

What You Need

• One flat bed sheet for your mattress size (or bigger)
• 50" in length of flat 3/16" or ¼" elastic
• Matching thread
• Scissors
• Pins
• Tape measure
• Serger (optional)
• Rotary cutter
• Cutting mat

Pro Tip: If you're using brand new flat sheets, pre-wash them before you cut. Otherwise, you could end up with fitted sheets that are too small, as a woven cotton can shrink significantly for a variety of reasons.

Instructions

1. Measure Your Bed

Make sure there's nothing on top of your bed except a mattress protector (if you use one). Measure exactly from one corded edge to the other, laying the measuring tape flat and straight on top of the mattress. Take the measurements for width, length and thickness. For a consistent look — and to make sure your fitted sheets will be on grain — snip and rip off two contiguous existing hems and measure from those raw edges.

2. Cut Your Flat Sheet

Now it's time to figure out your fabric measurements so you can cut your sheet. If you want a quick shortcut, you can use this free Fitted Sheets Calculator. Simply pop the three measurements (width, length and thickness) into the calculator and you'll instantly get your fabric measurements.

You can also calculate on your own, using the guidelines below:

Measurement A: Width of your mattress

Measurement B: Length of your mattress

Measurement C: Height of your mattress

Width: Start with the width of your mattress (Measurement A) and add the height twice (Measurement C x 2). Add another 5" for two seam allowances and extra fabric to slide under the mattress. This total will result in Measurement D.

Length: Add the length of your mattress (Measurement B), the height twice (Measurement C x 2) and an additional 5". This total will result in Measurement E.

Measurement D is the width of your fitted sheet, while Measurement E is the length. Cut your sheet to size.

Pro Tip: If your fabric has a pattern printed on it, make sure to cut so it goes in the right direction!

3. Cut the Sheet's Corners

Now you'll cut off each corner. The cut should be a square with a measurement of C + 3". This is measurement F. Here's an example of how your fabric measurements should look.

To make it easier to see, we demonstrated the cuts you'll make to your fitted sheet on a piece of scrap paper.

First, fold the fabric in half by length, then again in half by width. This will pile the four corners together in one spot.

Mark measurement F on both sides, starting from the corner.

Cut out the square using a rotary cutter and cutting mat.

Your fabric will look like the above image after it's cut.

4. Sew the Sheet Corners

With the right sides together, fold over the edges of one of the corners, matching the X and O shown in the image above.

Sew from the X and O mark to the point of the missing square, using a ½" seam allowance. Then trim and zigzag-stitch the edge, or serge the edge with a four-thread overlock.

Pro Tip: To make your fitted sheets even more durable, you can sew the corners with a French seam.

Repeat for the other three corners. Then try your WIP fitted sheet on the mattress to make sure you're on the right track.

5. Attach the Elastic

If you have a serger, run a three-thread overlock all around the raw edge. (As a shortcut, you can use a four-thread overlock so you don't have to pull one of the needles and one spool off!)

If you don't have a serger, press the entire raw edge ¼" toward the wrong side. Then, press a ½" hem toward the wrong side of the fabric.