Sewing Calculators
Bias Tape Length Calculator
Calculate how much bias tape you need to bind an edge based on the edge perimeter and overlap allowance.
Elastic Cut Length Calculator
Calculate the elastic length to cut based on a body measurement and a reduction percentage for a snug fit.
Fabric Shrinkage Calculator
Calculate fabric shrinkage percentage from a test swatch and the adjusted cut length needed to hit your desired finished size.
Fabric Yardage Calculator
Calculate how many yards of fabric to buy based on piece dimensions, quantity needed, seam allowance, and fabric bolt width.
Gathering/Ruffle Ratio Calculator
Calculate how much flat fabric you need to gather down to a desired finished ruffle length using a gather ratio.
Pattern Scaling Calculator
Calculate a new measurement when scaling a sewing pattern up or down by a percentage.
Quilt Batting Calculator
Calculate the batting and backing size needed for a quilt based on the quilt top dimensions and overhang margin.
Seam Allowance Calculator
Calculate the actual cut size of a fabric piece by adding seam allowance to a finished measurement.
Thread Length Estimator
Estimate how much sewing thread you'll need for a project based on total seam length and a thread usage multiplier.
Zipper Length Calculator
Calculate what length zipper to buy based on your finished opening length and installation allowance.
The Measurements Behind Every Sewing Project
Sewing runs on precise measurement: how much fabric to buy, how much to add for seam allowance, how far patterns scale up or down, how much a fabric will shrink on its first wash. Get any of these wrong and a project falls short of fabric or ends up with a botched fit. This category covers the standard formulas seamstresses and tailors rely on.
Calculate fabric yardage, seam allowance cut sizes, thread length, pattern scaling, shrinkage correction, bias tape and zipper length, quilt batting size, elastic cut length, and gathering ratios — the practical math behind planning and cutting any sewing project.