🎨 Thinning Ratio Calculator
Enter your paint volume, the unit, and the thinning percentage from the data sheet to see exactly how much thinner to add and the total volume once it's mixed — no guesswork, no over-thinning.
🎨 Mix the Right Ratio
What is a Thinning Ratio Calculator?
It turns a thinning percentage into an exact quantity. Tell it how much marine paint you're mixing and the percentage the manufacturer recommends, and it returns the volume of thinner to add and the total volume you'll end up with — in litres or millilitres.
Getting viscosity right is what makes a coating brush, roll, or spray cleanly and cure to full strength. Use this to mix consistent batches, keep the dry film thickness on target, and avoid the over-thinning that quietly undermines an otherwise good paint job.
❓ Frequently Asked Questions
How much thinner do I add to marine paint?
Multiply the paint volume by the thinning percentage the data sheet recommends. Ten percent thinning of five litres of paint means half a litre of thinner, for a total of 5.5 litres of mixed paint. This calculator does that in litres or millilitres and shows both the thinner to add and the total volume.
Why does thinning matter for a coating?
Thinner adjusts viscosity so the paint flows and levels correctly for the application method and temperature. Too little and the paint drags, leaves brush marks, or won't atomise when sprayed; too much and you drop the dry film thickness and weaken the coating. The right ratio is a balance the manufacturer sets.
Can I over-thin antifouling or topcoat?
Yes, and it's a common mistake. Over-thinning lowers the volume solids, so each coat leaves less dry film and you may fail to reach the specified thickness — meaning earlier fouling or coating breakdown. Stick to the recommended maximum on the data sheet and add thinner sparingly, checking the film as you go.
Which thinner should I use?
Always use the thinner the paint manufacturer specifies for that product. Coating chemistries are matched to particular solvents; the wrong thinner can stop the paint curing, cause it to gel, or ruin adhesion. If in doubt, buy the branded thinner listed on the tin rather than a generic substitute.