Acrylic Pouring Paint Calculator (How Much Paint for a Pour)
Work out how much paint mix an acrylic pour needs for your canvas size, sides included, then split it into pouring medium and paint by ratio and into cups per colour.
How it works
surface = top (width × height, or π × r² for round) + sides (edge depth × perimeter) · paint mix = surface (sq in) ÷ 16 (standard), ÷ 20 (light) or ÷ 12 (heavy) fluid ounces · 1 fl oz = 29.57 ml, 1 sq in = 6.45 cm² · medium = mix × ratio ÷ (ratio + 1), paint = mix ÷ (ratio + 1)
The rule of thumb most pour artists use is about one fluid ounce of mixed paint for every 16 square inches of surface, counting the sides of the canvas if you want them covered. Thin flat pours can get away with less; techniques that move a lot of paint off the edge — swipes, dome, ring and tree pours — need more. The mix is pouring medium (such as Floetrol or a dedicated pouring medium) and acrylic paint: fluid paints need about 1:1, soft-body paints 2:1 and heavy-body paints 3:1, plus a little water until the mix flows like warm honey. Always mix 10% extra because some paint stays in the cups.
Worked example
A 30 × 40 cm canvas with 2 cm sides has 1,200 + 280 = 1,480 cm² (229 sq in) to cover. At the standard 1 fl oz per 16 sq in you need about 424 ml of paint mix: 283 ml of pouring medium and 141 ml of paint at 2:1, or 106 ml of mix per colour for four colours.
Sources: LeftBrainedArtist — How much paint to use for an acrylic pour · Wikipedia — Acrylic paint
Frequently asked questions
How much paint do I need for a 12 × 12 canvas?
About 9–11 fl oz (270–330 ml) of mixed paint for the top alone at 1 fl oz per 16 sq in, and a little more if you cover 1.5 in deep sides.
What ratio of Floetrol to paint should I use?
A common starting point is 2 parts Floetrol to 1 part soft-body acrylic, then add water a few drops at a time until the mix flows like warm honey. Fluid acrylics need closer to 1:1.
Should I include the sides of the canvas?
Yes if you want them covered — on a gallery-wrapped canvas the sides can add 20–30% to the area. Set the edge depth to 0 if you will tape them or paint them separately.
How do I avoid running out of paint mid-pour?
Mix 10–20% extra, keep one colour (often white) in a larger cup, and save leftovers in airtight cups for a second small canvas or coasters.
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This calculator is for educational purposes. Double-check important results before acting on them.