Cushion Fabric Calculator

Get the exact yardage for cushions and seat pads. Choose a standard cushion size or enter custom dimensions.

Calculate Cushion Yardage

Select a standard cushion size or enter custom dimensions. For cushions with a boxing strip (side panel), check the box below.

Chair Pad 16x18"
Bench 48x18"
Window Seat 72x20"
Outdoor Chaise 72x24"
Boat Seat 18x18"

How to Calculate Cushion Fabric Yardage

Calculating fabric for a cushion involves three components: the top piece, the bottom piece, and (optionally) the boxing strip that wraps around the sides. The wider the fabric, the fewer rows you need.

Without boxing strip:
Piece size = (Length + seam x 2) x (Width + seam x 2) — cut 2 per cushion (top + bottom)

With boxing strip:
Top/Bottom = (Length + seam x 2) x (Width + seam x 2) — cut 2 per cushion
Boxing strip = (Length x 2 + Width x 2 + seam allowance) x Depth — cut 1 per cushion

Total rows = Total inches needed / Fabric width (rounded up)
Yardage = Rows x piece length / 36

Cushion Yardage Chart by Type

Estimated yardage for common cushion types using 54" decor fabric with 0.5" seam allowance and 4" depth (where boxing applies).

Cushion TypeDimensionsBoxing StripYardage (1 cushion)
Chair Pad16x18"No1/2 yard
Chair Pad16x18"Yes (4")3/4 yard
Dining Bench48x18"No1 yard
Dining Bench48x18"Yes (4")1 1/4 yards
Window Seat72x20"No1 1/2 yards
Window Seat72x20"Yes (4")2 yards
Outdoor Chaise72x24"Yes (5")2 1/4 yards
Boat Seat18x18"Yes (3")7/8 yard

With vs Without Boxing Strip

Without a boxing strip, the top and bottom pieces are sewn directly together — ideal for flat, thin seat pads like basic chair pads or lightweight cushions. The yardage is simply two identical rectangles per cushion.

With a boxing strip, a separate side panel wraps around the cushion's thickness. This adds a rectangular strip around the perimeter: (Length + Width) x 2, plus seam allowance, multiplied by the cushion depth. Boxing strips give cushions a professional, finished look and accommodate thicker foam padding for comfort. For deep cushions (4" or more), the boxing strip can require as much fabric as the top piece itself.

As a rule of thumb, adding a 4" boxing strip increases fabric needs by 30–50% compared to a flat cushion of the same size.

Frequently Asked Questions

How much extra fabric should I buy for cushion seams?
A 1/2" seam allowance is standard for most cushion projects. This adds 1" to both the length and width of each piece. If you are a beginner, consider using a 5/8" seam allowance for easier handling. Always add seam allowance to both the top and bottom pieces, and to boxing strips as well.
Do I need a boxing strip for outdoor cushion covers?
Yes, outdoor cushions almost always use boxing strips because they are typically 4–6" thick to provide comfort on hard patio furniture surfaces. A boxing strip also helps the cover fit snugly over thick foam. Use outdoor-rated fabric (typically 54" wide, solution-dyed acrylic or polyester) for best durability.
What is the best fabric width for cushion making?
54" wide decorator fabric is the most common choice for cushion projects. It allows most cushion sizes to fit 2 pieces side by side across the width, minimizing waste. For large bench or window seat cushions (72" or longer), 60" upholstery fabric may be more efficient as it can often fit the entire length in one row.
How do I calculate yardage for a bench cushion?
Measure the bench seat length (front to back) and width (side to side). Multiply by 2 for the top and bottom pieces, then add the boxing strip: (length + width) x 2 x depth. Divide the total inches by the fabric width to get the number of rows needed, then multiply rows by the piece length and divide by 36 to get yards. Our calculator above does this automatically for you.
Should I buy extra yardage for pattern matching?
Yes, if your fabric has a repeating pattern (stripes, plaids, or large motifs), add 15–25% to the calculated yardage. Pattern matching requires aligning the design across seams, which uses more fabric. For solid fabrics or small-scale prints, the standard 10% waste allowance is usually sufficient.