🖋️ Ink Mixing Ratio Calculator

Parts are shared out of the total, not added to it

You give a finished volume and a ratio; the tool splits that volume in proportion rather than adding water on top of a full pot of ink:

ink ml   = total × ink parts / (ink parts + water parts)
water ml = total × water parts / (ink parts + water parts)

30 ml at 2:1  →  30 × 2/3 = 20.0 ml ink + 30 × 1/3 = 10.0 ml water

So a 2:1 mix is two thirds ink, or 66.7%, not half. Set both parts to 1 and the same 30 ml splits 15.0 and 15.0. A thin gouache wash at 1:3 in a 20 ml jar gives 5.0 ml colour to 15.0 ml water. Figures are rounded to one decimal place.

Working with the numbers at the desk

• Half-part steps are allowed. The parts boxes move in 0.5, so 5:1 and 4.5:1 are both expressible.
• Mix a little more than the job needs. A pipette leaves ink behind, gouache settles, and topping up mid-piece never quite matches.
• Write the ratio on the jar, not the millilitres. The ratio is what you reproduce next month.

Frequently asked questions