Paint Dilution and Mixing Ratio Calculator
Calculate how much thinner to add for a desired dilution ratio, or determine proportions when mixing multiple paint colors together.
Formulas Used
Dilution by Ratio (Paint : Thinner = P : T):
- Thinner needed = Paint Amount × (T / P)
- Total mixture = Paint Amount + Thinner needed
- Paint % in mixture = P / (P + T) × 100
- Thinner % in mixture = T / (P + T) × 100
Dilution by Percentage (D%):
- Thinner needed = Paint Amount × (D / 100)
- Total mixture = Paint Amount × (1 + D / 100)
Color Mixing:
- Total parts = r₁ + r₂ + … + rₙ
- Volume of color i = Target Volume × (rᵢ / Total parts)
- Percentage of color i = (rᵢ / Total parts) × 100
Assumptions & References
- All paints and thinners are assumed to have equal density (volume-based mixing).
- Dilution percentage is defined as thinner volume relative to paint volume (not total mixture).
- Ratio inputs represent parts by volume (e.g., 2:1 means 2 volumes paint to 1 volume thinner).
- Unit conversions: 1 L = 1000 ml; 1 fl oz ≈ 29.5735 ml; 1 gal = 3785.41 ml.
- Typical spray paint dilution: 10–20% thinner; airbrush: 50–100%; brush: 5–15%.
- Always consult your paint manufacturer's data sheet for recommended dilution ratios.
- Color mixing results are by volume; actual color appearance depends on pigment concentration.