The Acrylic Pour Paint Calculator tells you how much paint mix to prepare for a fluid art pour. It covers the canvas top and sides, adds a runoff allowance for the paint that drips off, and splits the total into acrylic paint and pouring medium using your ratio.
Acrylic Pour Paint Calculator
How much paint mix you need for an acrylic pour on a canvas — including the sides and runoff — and how to split it into paint and pouring medium.
It works for rectangular and round canvases. Results are in US fluid ounces and milliliters.
Formula
Rectangular: V = (w × h + 2(w + h) × d) × t × (1 + runoff)
Round: V = (πD² ÷ 4 + πD × d) × t × (1 + runoff)
Paint = V × paint parts ÷ (paint + medium parts)
Where w, h = canvas width and height, D = diameter, d = side depth, t = layer thickness.
How the Calculation Works
Step 1: Surface area = top + sides.
Step 2: Multiply by layer thickness for volume.
Step 3: Add the runoff allowance.
Step 4: Split by your paint : medium ratio.
Example Calculation
12 × 12 in canvas
Given: 1.5 in deep sides, 1 mm layer, 50% runoff, 1 : 2 paint to medium
- Area = 144 + 2 × 24 × 1.5 = 216 in²
- Volume = 216 × 0.03937 in × 1.5 ≈ 12.76 in³ ≈ 7.07 fl oz (≈ 209 mL)
- Paint ≈ 2.36 fl oz; medium ≈ 4.71 fl oz
12 in round canvas
Given: 0.75 in sides, 1 mm layer, 50% runoff
Area = 113.1 + 28.3 = 141.4 in² → ≈ 4.63 fl oz of mix
Variables Explained
| Input | Meaning |
|---|---|
| Layer thickness | How thick the poured layer is; thicker pours use more paint |
| Runoff allowance | Extra for paint that runs off the edges |
| Paint / medium parts | Your mixing ratio — it depends on the paint’s consistency and the medium |
Frequently Asked Questions
How much paint do I need for an acrylic pour?
Canvas area (top and sides) × layer thickness, plus runoff — the calculator does it in fluid ounces.
How much paint for a 16 × 20 canvas?
Enter 16 and 20 with your side depth; larger canvases scale with area.
What ratio of paint to pouring medium?
It depends on the products; many artists test consistency and adjust. Enter your ratio.
Do I need to cover the sides?
If you want paint on the edges, yes — set side depth to 0 to skip them.
Why add runoff?
Some paint always flows off the canvas during tilting.