How to Calculate Fabric Yardage
The complete guide to calculating how much fabric you need — by hand or with our calculator. Covers the core formula, adjustments for width, pattern repeat, and overage.
Fabric yardage math is straightforward once you split it into clear steps. This guide explains each part of the calculation in plain terms, so you can check numbers before you buy fabric. You will see how base yardage, width, pattern repeat, and overage work together. By the end, you can calculate by hand or use the same logic in the calculator with confidence.
The Core Formula
Every fabric yardage calculation follows the same basic structure:
Base Yardage × Width Adjustment × Pattern Repeat × Overage = Total Yardage
Each factor depends on your project type. Let’s break them down.
Step 1: Determine Base Yardage
Base yardage is the starting amount for your project at a standard fabric width with no pattern and no overage.
- Upholstery: Use the standard range for your furniture type. A sofa is 12–16 yards at 54 inches. See the upholstery yardage chart.
- Garments: Check your pattern envelope or use standard yardage for the garment type and size. A medium dress is about 3 yards at 45 inches.
- Curtains: Calculated from window width, drop length, and fullness ratio.
- Quilting: Calculated from quilt dimensions and number of fabric colours.
Step 2: Adjust for Fabric Width
Fabric width directly affects yardage. Wider fabric = less yardage needed, because more pattern pieces fit side by side.
The adjustment formula is simple:
Width Adjustment = Standard Width ÷ Your Fabric Width
For upholstery (standard 54 inches): if your fabric is 45 inches wide, the adjustment is 54 ÷ 45 = 1.2 — you need 20% more fabric.
For garments (standard 45 inches): if your fabric is 60 inches wide, the adjustment is 45 ÷ 60 = 0.75 — you need 25% less fabric.
See the width comparison reference for a detailed explanation.
Step 3: Account for Pattern Repeat
If your fabric has a repeating pattern, you need extra fabric to align the pattern across seams. The multiplier depends on the repeat size:
| Repeat Size | Repeat Distance | Multiplier | Extra Fabric |
|---|---|---|---|
| None / solid | 0" | 1.0 | +0% |
| Small | Up to 6" | 1.1 | +10% |
| Medium | 6–12" | 1.2 | +20% |
| Large | 12"+ | 1.35 | +35% |
Read the full pattern repeat guide for measuring and matching techniques.
Step 4: Add Overage
Always buy more than the calculated minimum. Fabric from different dye lots can have subtle colour differences, and mistakes happen.
- 10% — minimum for plain fabrics with no pattern
- 15% — recommended for most projects
- 20% — for your first project or complex designs
Worked Example: Sofa Reupholstery
Project: Standard 3-seat sofa
Fabric: 45-inch wide, medium pattern repeat (8-inch repeat)
Overage: 10%
Step 1: Base yardage for a sofa = 14 yards (midpoint of 12–16 range)
Step 2: Width adjustment = 54 ÷ 45 = 1.2
Step 3: Pattern repeat = × 1.2 (medium)
Step 4: Overage = × 1.1 (10%)
Total: 14 × 1.2 × 1.2 × 1.1 = 22.18 yards → round up to 22.25 yards
Or skip the math — enter these details in our upholstery calculator and get the answer instantly.
Always Round Up
Round to the nearest 0.25 yard (quarter yard). Fabric retailers cut in quarter-yard increments, and rounding up ensures you never run short. The extra cost of 0.25 yards is negligible compared to the risk of running out mid-project.