Sewing calculators
Quick answers to the maths of sewing: circle skirt radius, how much fabric to buy, sizes across countries, gathering, elastic, binding, allowances and buttons.
Circle skirt calculator
Enter your waist and the length you want: you get the waist radius to draw, the hem circumference and how much 110, 140 or 150 cm (45, 55 or 60 in) fabric to buy, for a full, three-quarter, half or quarter circle.
Open the calculator →Fabric yardage calculator
Choose a garment, a standard size or your own measurements, and a fabric width: the calculator drafts the pattern pieces with Sewly's engine, lays them out on folded fabric and tells you how much to buy, in meters and yards.
Open the calculator →Sewing size converter (EU, US, UK)
Pick a size to see it in every system with the body measurements behind it, or enter your measurements to find the closest size, for women, men and children.
Open the calculator →Gathering ratio calculator
Enter the length the gathers must fit and a gathering ratio: you get the length of fabric to gather, how many panels to cut across your fabric's width and how much fabric to buy.
Open the calculator →Elastic length calculator
Enter the measurement where the elastic will sit and how firm the elastic is: you get the finished loop and the length to cut, overlap included, for waistbands, wrists, ankles or sleeves.
Open the calculator →Bias binding calculator
Add up the edges to bind, choose the finished width and the type of binding: you get the binding length, the width to cut the strips and the size of fabric square that makes it as continuous bias.
Open the calculator →Seam allowance converter (cm and inches)
Type a seam allowance in centimeters or inches: you get it in the other unit, as the fractions on your sewing gauge, with the closest common allowance and how much they differ.
Open the calculator →Button spacing calculator
Enter the length of the opening, how many buttons you want and where the first and last go: the calculator spaces the rest evenly and lists every position from the top edge, in centimeters or inches.
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