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Calculator Collection

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Both calculators run independently β€” change the inputs on either side to compare results.

Sewing

Fabric Gathering Ratio Calculator

Calculate the pre-gathered fabric length needed to achieve the right fullness for ruffles, skirt hems, and sleeves. Accounts for gathering ratio, fabric drape, and hem allowances.

Fill in the required fields to see your result.
Sewing

Seam Allowance Fabric Calculator

Calculate how much extra fabric you need when changing the seam allowance from what a pattern specifies. Essential when adapting European (1 cm) patterns to US (5/8 inch) standards, or vice versa.

Fill in the required fields to see your result.

Key differences

Fabric Gathering Ratio CalculatorSeam Allowance Fabric Calculator
CategorySewingSewing
Inputs required44
ResultFabric Length to Cut (inches)Adjusted Fabric Needed (yards)
What it doesCalculate the pre-gathered fabric length needed to achieve the right fullness for ruffles, skirt hems, and sleeves. Accounts for gathering ratio, fabric drape, and hem allowances.Calculate how much extra fabric you need when changing the seam allowance from what a pattern specifies. Essential when adapting European (1 cm) patterns to US (5/8 inch) standards, or vice versa.