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6.667
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3.333
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3
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6.667
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3.333
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Getting a consistent, reproducible paint mix is one of the most challenging aspects of scale modeling. Whether you're mixing custom colors for a unique camouflage scheme, blending flesh tones for miniature figures, or thinning acrylic paint to the right consistency for airbrushing, understanding paint ratios is the key to professional-quality results that you can replicate across a project that may span weeks or months.
The Paint Mixing Ratio Calculator converts any ratio-based formula into exact milliliter quantities based on the total volume you need. Instead of guessing or eyeballing dropper amounts, you get precise measurements for each component — giving you the confidence to mix larger or smaller batches while maintaining the exact same color and consistency.
Paint mixing ratios are typically expressed as parts — a ratio like 2:1:0.5 means two parts of Color A to one part of Color B to half a part of Color C. The beauty of this system is its scalability: the same ratio produces identical results whether you're mixing 2 ml or 20 ml. This calculator takes your ratio and your required volume and tells you exactly how much of each component to measure out.
For miniature painters using Games Workshop, Vallejo, or Citadel paints, mixing custom colors is a regular practice. Skin tones, weathering washes, OSL (Object Source Lighting) blends, and NMM (Non-Metallic Metal) highlights all require careful color mixing. Noting your ratios and using this calculator ensures that if you need to remix a color weeks later, you can match it precisely rather than starting from scratch and hoping for the best.
Airbrushing adds another dimension to paint mixing: thinning. Most acrylics need to be thinned to a consistency often described as 'skimmed milk' for airbrushing. A typical starting ratio is 1:1 to 2:1 paint to thinner, though this varies by paint brand, nozzle size, and air pressure. This calculator includes a thinner field specifically for airbrushing applications, and the paint-to-thinner ratio output gives you a quick reference number to note in your records.
Enamel and oil paints used for weathering — pin washes, filters, and chipping — are typically thinned much more aggressively, sometimes 5:1 or even 10:1 thinner to paint for the most transparent filters. The calculator handles all these cases identically, regardless of the specific ratio values you enter.
For scale modelers, keeping a small notebook of your paint mixing recipes is invaluable. Record the color names, the ratio, and the total volume mixed each time. Over time, this builds a personal library of proven mixtures that you can return to for future projects with the same color requirements.
The calculator adds all parts together to find the total number of parts, then calculates what fraction of the total each component represents. That fraction is multiplied by the total volume needed to give the volume of each component. For example, a 2:1 mix for 9 ml total gives 3 total parts: Color A = (2/3) × 9 = 6 ml, Color B = (1/3) × 9 = 3 ml. The paint-to-thinner ratio divides total paint parts by thinner parts, giving a simple reference number like 1.5 (meaning 1.5 parts paint per 1 part thinner).
Each volume output tells you exactly how many milliliters to measure for that component. Use a precision dropper (most hobby paint bottles dispense approximately 0.03–0.05 ml per drop, or about 20–25 drops per ml) or a small graduated syringe for accuracy. The paint-to-thinner ratio is particularly useful for airbrushing: values between 1.0 and 2.0 are typical for most acrylic airbrush work. If Color C is not used, set its parts to 0 and ignore that output.
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A 3:1:0.5 paint ratio thinned 2 parts produces a paint-to-thinner ratio of 2.25:1, suitable for airbrushing with a 0.3 mm nozzle at medium air pressure.
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A 4:2:1 skin tone blend (base flesh : warm white : medium flesh) in a 3.5 ml total gives precise dropper amounts for brush-on painting of miniature figures.
The most practical tools are: (1) a 1 ml plastic syringe — available cheaply at pharmacies and hobby shops; (2) a precision dropper — most hobby paint dropper bottles dispense roughly 20–25 drops per ml; (3) a jeweler's scale that measures to 0.01 g accuracy, since most hobby paints have a density very close to 1 g/ml. For very small mixes under 0.5 ml, counting drops is the most practical approach.
Dedicated acrylic thinners from Vallejo, Tamiya, or Mr. Hobby give the best results. Distilled water works as a basic thinner but can reduce flow and affect drying time. Isopropyl alcohol (IPA) at 70–91% concentration thins well but dries very fast — useful for airbrushing but not ideal for brush work. Airbrush medium (retarder) mixed in small amounts (5–10%) helps with tip-dry in hot conditions.
Yes, this calculator works for any volumetric ratio, including two-part epoxy paints and primers which are typically mixed 1:1 or 2:1. Enter the resin parts as Color A and the hardener parts as Color B, set Color C and thinner to 0, and enter your desired total volume. The volumetric amounts given will be correct as long as you are mixing by volume (not by weight — some epoxies specify weight ratios).
Write down: the paint brand and color names for each component, the parts ratio (e.g., 3:1:0.5), and optionally the total volume you mixed. This is all you need to reproduce the color later using this calculator. Many modelers also paint a small sample on a piece of card and attach it to their notes as a visual reference.
A good starting point is 1:1 (equal parts paint and thinner) for most acrylic paints through a 0.3–0.4 mm nozzle at 15–20 PSI. Thinner paints (higher thinner ratio) allow lower pressure and finer lines but reduce opacity, requiring more coats. Pre-thinned paints like Vallejo Air and Tamiya X series often need minimal additional thinning. Always test on scrap first.
Not exactly, because paint mixing is subtractive (pigment-based) rather than additive (light-based), and different pigments have different tinting strengths. A 1:1 mix of two colors will not necessarily produce a perceptually equal blend — the color with the stronger tinting power will dominate. Adjust ratios iteratively when matching a specific reference color.
Yes, the ratio stays constant regardless of volume. If you originally mixed 5 ml and want 50 ml, multiply all volumes by 10. This calculator handles any volume — enter 50, 100, or 500 ml as needed for terrain boards, large vehicle collections, or batch painting armies.
Roboculator Team
The Roboculator Team explains calculations, planning tools, and practical formulas in clear language for real-life situations.
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