How to Sew Fitted Bed Sheets

by Elizabeth / Sunday, 16 April 2023 / Published in Bedding

Sewing fitted bed sheets is a rewarding project that allows you to customize your bedding to your exact needs and preferences. This detailed guide will walk you through each step, from measuring your mattress to adding the final elastic.

1. Gathering Your Supplies and Measuring Your Mattress

Before you begin, gather the following materials:

Fabric: Choose a fabric that suits your preference, such as cotton, linen, or silk. The amount needed will depend on your mattress size, but generally, you’ll need a piece at least as wide and long as your mattress, plus extra for seam allowance and the drop.
Elastic: A good quality elastic, typically 1/4 inch or 3/8 inch wide, is best for this project.
Sewing Machine: A reliable sewing machine is essential.
Scissors or Rotary Cutter: For cutting fabric accurately.
Measuring Tape: For measuring the mattress and fabric.
Pins: To hold the fabric in place while sewing.
Thread: Matching thread to your fabric.
Safety Pin: To thread the elastic.
Iron: For pressing seams.

Measuring the Mattress

Accurate measurements are crucial for a well-fitting sheet. Measure the following:

Length (L): Measure from the top to the bottom of the mattress.
Width (W): Measure from side to side of the mattress.
Thickness (T): Measure the height of the mattress.

Calculating Fabric Dimensions

To calculate the fabric you’ll need, use these formulas:

Fabric Length = Length (L) + (2 x Thickness (T)) + (2 x Hem Allowance) + (4 x Corner Depth)
Fabric Width = Width (W) + (2 x Thickness (T)) + (2 x Hem Allowance) + (4 x Corner Depth)

Hem Allowance: This is typically 1 inch. Corner Depth: This is the distance from the corner of your mattress to where the elastic will sit under the mattress. It’s typically the thickness measurement plus a bit more to securely tuck under the mattress. A good rule of thumb is to add 1-3 inches to the thickness measurement (T) as corner depth, depending on how tightly you want the elastic to grip the mattress. A corner depth of 2-4 inches is typical for most mattresses.

For example, if your mattress measures 75 inches long (L), 54 inches wide (W), and 10 inches thick (T), and you choose a hem allowance of 1 inch, and a corner depth of 3 inches:

Fabric Length = 75 + (2 x 10) + (2 x 1) + (4 x 3) = 75 + 20 + 2 + 12 = 109 inches
Fabric Width = 54 + (2 x 10) + (2 x 1) + (4 x 3) = 54 + 20 + 2 + 12 = 88 inches

You will need a piece of fabric at least 109 inches long and 88 inches wide. Always add a bit more to be safe.

Measurement	Description	Calculation Example (Mattress: L=75, W=54, T=10, Hem =1″, Corner Depth =3″)
Mattress Length (L)	Length of the mattress from top to bottom	75 inches
Mattress Width (W)	Width of the mattress from side to side	54 inches
Mattress Thickness (T)	Height of the mattress	10 inches
Hem Allowance	The amount of fabric used for hemming (typically 1 inch)	1 inch
Corner Depth	The distance from the corner of your mattress to where elastic will sit	3 inches
Fabric Length	L + (2 x T) + (2 x Hem) + (4 x Corner Depth)	109 inches
Fabric Width	W + (2 x T) + (2 x Hem) + (4 x Corner Depth)	88 inches

2. Cutting the Fabric and Creating the Corners

Cut the Fabric: Lay your fabric on a flat surface and cut it according to the dimensions you calculated.
Prepare the Corners: The most common method is to create a box corner. This involves cutting squares from each corner of the fabric.
- To determine the size of the squares, use this formula: Corner Square Size = Thickness (T) + Corner Depth.
- Using the previous example, Corner Square Size = 10 + 3 = 13 inches.
- Cut out a 13×13 inch square from each corner.
Create the Box Corners:
- Fold and pin each corner so that the edges of the cut-out squares meet.
- Sew along the pinned edge with a straight stitch using a 1/2 inch seam allowance. This will create a box-like corner.
- Reinforce your seams by sewing again over the initial stitch and backstitching at the start and end of the seam.
- Trim excess fabric, making sure not to cut into the stitching.
- Press the seams open with an iron.

3. Hemming and Creating the Elastic Casing

Hem the Edge: Fold over the raw edge of the fabric by 1/4 inch and then another 1/4 inch to create a double-folded hem. Pin this hem all the way around the entire sheet.
Sew the Hem: Stitch the hem using a straight stitch along the entire edge. Leave about 2-3 inches open in the hem on a short side of the sheet for inserting the elastic.
Create the Casing: Sew a second line of stitching about 3/4-inch (1.5 cm) away from the first seam to create a channel for the elastic. Be sure to leave the gap for the elastic open.

4. Inserting the Elastic

Attach the Safety Pin: Attach the safety pin to one end of your elastic.
Thread the Elastic: Use the safety pin to guide the elastic through the casing you created in the previous step. Be sure to hold on to the other end of your elastic so it doesn’t disappear into the casing.
Adjust the Elastic: Once the elastic is threaded through, gently pull it until the sheet fits nicely around the mattress. You’ll want to pull it tight enough that the sheet will grip but not so tight that the sheet becomes puckered and unusable.
Secure the Elastic: Overlap the ends of the elastic by about an inch and sew them together with a tight zig-zag stitch or multiple straight stitches for added security.
Close the Casing: Close the remaining opening in the hem by carefully stitching it shut.

5. Final Touches

Press the Sheet: Give your completed sheet a final press with an iron to remove any wrinkles and ensure a crisp finish.
Test the Fit: Place the sheet on your mattress and make any adjustments if needed.
Enjoy Your Custom Sheet: Now, your new fitted sheet is ready for use.

Special Considerations for Silk

When working with silk, consider the following:

Use Sharp Needles: Silk is delicate, so use a new, sharp needle to prevent snags or runs in the fabric.
Handle Gently: Silk can shift easily. Use plenty of pins to secure it while cutting and sewing.
Low-Heat Ironing: Iron silk on a low heat setting and use a pressing cloth to protect the fabric.
Choose High-Quality Elastic: High-quality elastic will last longer and maintain it’s stretch to provide a secure fit for your silk bedsheets. When choosing elastic, prioritize materials like rubber and polyester for longevity and elasticity. The elastic for a silk sheet should be a similar color to the fabric so that it doesn’t show through the fabric.
High-Quality Thread: Use a fine, high-quality thread to match the delicacy of the silk fabric to ensure it will not break and ruin the seams and fit of the sheet.
Consider Pre-Washing: Pre-washing silk fabric can help prevent shrinkage, but it is not always advisable as silk’s delicate nature can be impacted negatively. Instead, consider a gentle hand wash or professional dry cleaning.