Free Fabric Calculator Online

Looking to calculate exactly how much fabric you need for your next sewing project? use this free fabric calculator for precise fabric measurements.

Let’s say you’re making curtains for a large window. The window measures 72 inches wide and 60 inches long, and you want the curtains to have a fullness factor of 2.5 (meaning they’ll be 2.5 times wider than the window when gathered). You also need to account for a 1-inch seam allowance on all sides and a 4-inch hem at the bottom.

Using online fabric calculator, you’d input these measurements:

Width: 72 inches × 2.5 (fullness factor) + 2 inches (seam allowances) = 182 inches

Length: 60 inches + 1 inch (top seam) + 4 inches (bottom hem) = 65 inches

The calculator would then determine that you need approximately 5.5 yards of 54-inch wide fabric for your curtain project.

Fabric Calculation Chart

Fabric Measurement Formula

The fabric measurement formula can be expressed as:

Total Fabric Needed = (Project Width + Seam Allowances) × (Project Length + Seam Allowances + Extras) ÷ Fabric Width

• Bag dimensions: 14 inches wide × 16 inches tall
• Seam allowance: 1/2 inch on all sides
• Extra for handles: 4 inches
• Fabric width: 45 inches

Circular Projects Formula:

π × (radius + seam allowance)²

Single Panel Curtain Formula:

(Window Width ÷ 2) × Fullness + Seam Allowance

Plugging these numbers into formula:

Total Fabric Needed = (14 + 1) × (16 + 1 + 4) ÷ 45
= 15 × 21 ÷ 45
= 315 ÷ 45
= 7 inches (or 0.19 yards)

This calculation tells us we need approximately 1/5 of a yard to create our tote bag.

How Do I Calculate How Much Fabric I Need?

Calculating fabric requirements involves several steps:

Find the finished dimensions of your project.

Add seam allowances to all sides.

Include any extra fabric needed for hems, pleats, or matching patterns.

Consider the fabric width you’ll be working with.

Use the fabric measurement formula to calculate the yardage.

Let’s walk through an example of making a simple skirt:

• Finished dimensions: 25 inches long, 30 inches waist circumference
• Seam allowances: 1/2 inch on sides, 1 inch for waistband, 1 inch for hem
• Extra fabric: Double the waist measurement for gathering (60 inches total width)
• Fabric width: 45 inches

Calculation:

Width needed: 60 inches + 1 inch (seam allowances) = 61 inches

Length needed: 25 inches + 1 inch (waistband) + 1 inch (hem) + 1 inch (seam allowances) = 28 inches

Using formula: Total Fabric Needed = 61 × 28 ÷ 45 = 37.9 inches (or 1.05 yards)

Therefore, you would need to purchase 1 1/8 yards of fabric for this skirt project.