Fabric Dye Calculator

Dye recipes are quoted as a shade depth: the mass of dye powder as a percentage of the dry mass of the fabric, often written % WOF (weight of fibre). A 2 % depth on 200 g of fabric is therefore 200 × 0.02 = 4 g of dye. The bath ratio is how much water that fabric is dyed in, given as litres per kilogram, so a 10 : 1 bath for the same piece is 200 × 10 ÷ 1000 = 2 L. Choosing the size route instead multiplies length × width to get square metres and then applies the fabric's gsm, which is why a 150 cm × 100 cm piece of 150 gsm cotton counts as 225 g. The calculator does the arithmetic only: powder strength differs between dye classes, and salt, soda ash, temperature, time and pH come from the dye maker's own recipe, so the grams here assume the stated shade depth is fully taken up by the fabric. Wash and weigh the fabric dry, and follow the product instructions and local disposal rules for the dye you are using. Everything is computed in your browser: nothing is stored or sent anywhere.