Indigo Vat Calculator

Chemical quantities for indigo reduction vat.

Fabric weight (kg)

Indigo depth (% OWF)

Reducer-to-indigo ratio

Alkali-to-indigo ratio

Vat volume (L)

Tab to move between fields

Indigo powder (g)

Reducing agent (g)120

Alkali (g)80

Indigo concentration (g/L)2

Estimated dip cycles3

How to Use This Calculator

How the result changes with Fabric weight (kg)

Fabric weight (kg): Dry weight of fabric or yarn to dye in kilograms.
Indigo depth (% OWF): Target indigo percentage on weight of fiber. Light: 1-2%, medium: 3-5%, dark: 6-10%.
Reducer-to-indigo ratio: Weight of reducing agent per unit indigo. Fructose/lime vat: 3:1, hydrosulfite: 2:1, iron: 3:1.
Alkali-to-indigo ratio: Weight of alkali (lime, soda ash) per unit indigo. Lime vat: 2:1, lye vat: 1:1.
Vat volume (L): Total volume of the vat in liters.

Indigo powder (g): Weight of indigo powder needed.
Reducing agent (g): Weight of fructose, hydrosulfite, or ferrous sulfate.
Alkali (g): Weight of calcium hydroxide, soda ash, or lye.
Indigo concentration (g/L): Indigo concentration in the vat.
Estimated dip cycles: Approximate number of dip-and-oxidize cycles needed for target depth.

Identify Input Parameters
4 parameters
Fabric weight (kg) = 1, Indigo depth (% OWF) = 4, Reducer-to-indigo ratio = 3, Alkali-to-indigo ratio = 2 = 5 input(s) provided
Calculate Indigo powder
Indigo powder = fabricWeightG * (indigoPctOwf / 100)
40 = 40
Calculate Reducing agent
Reducing agent = indigoNeededG * reducerRatio
120 = 120
Calculate Alkali
Alkali = indigoNeededG * alkaliRatio
80 = 80