Use this calculator to turn a lab recipe into a bulk recipe. Enter the batch weight and liquor ratio, then the shade % of each dye. It gives you the grams of each dye, the water in the machine, and the salt and soda for that shade depth.
How it works
- Water = fabric weight (kg) × liquor ratio. 500 kg at 1:8 is 4,000 L.
- Dye (g) = fabric weight (kg) × 1000 × shade % ÷ 100.
- Salt and soda (kg) = g/L × litres ÷ 1000. The g/L is picked from the shade table by the total shade %.
- Other chemicals can be added in g/L (on the water) or in % (on the fabric weight).
The salt and soda table is a typical starting point for reactive dyes on cotton. Every dye range and every floor is a little different: set the table to your own values and the calculator remembers them on your device.
Always confirm a new recipe with a lab dip before bulk. For the dyeing curves behind these numbers, see the 100% cotton dyeing process.
Questions
How do you calculate dye quantity from shade %?
Dye in grams = fabric weight in kg × 1000 × shade % ÷ 100. For 500 kg of fabric at 1.2% shade, that is 500 × 1000 × 1.2 ÷ 100 = 6,000 g of dye.
How do you calculate salt and soda from g/L?
First find the water: fabric weight × liquor ratio. Then chemical in kg = g/L × litres of water ÷ 1000. At 1:8 and 500 kg, the bath is 4,000 L, so 50 g/L salt is 200 kg.
Why do salt and soda depend on the shade %?
Deeper shades need more salt to push the reactive dye onto the cotton and more soda to fix it. Light shades need less, and too much salt on a light shade can make it unlevel.