Mixing hair colour correctly is one of the most important skills in hairdressing. Whether you’re a seasoned stylist or just starting out, understanding how to combine colour and developer (also called peroxide) is essential for achieving consistent, professional results. This guide explains how mixing works, why ratios matter, and how to use our Hair Colour Mix Ratio Calculator to take the guesswork out of the process.
How to Use the Hair Colour Mix Ratio Calculator
Our calculator is designed to make mixing effortless. Here’s how it works:
- Enter your ratio – For example, 1:1, 1:1.5, or 1:2.
- Input either the colour or developer amount – Whichever you know first.
- The calculator fills in the missing value – Instantly giving you the exact measurement needed.
This means no more mental maths, no more scribbling on colour boxes, and no more wasted product.
Step-by-Step Example
Example 1: Known Colour Volume
You want to use 40ml of colour at a 1:1.5 ratio. Enter 40ml under colour, and the calculator tells you to add 60ml of developer.
Example 2: Known Developer Volume
You have 90ml of developer and need a 1:1.5 ratio. Enter 90ml under developer, and the calculator tells you to add 60ml of colour.
Example 3: Lightener Mix
You’re mixing bleach powder at a 1:2 ratio. If you measure 25g of powder, the calculator tells you to add 50ml of developer.
What Is Developer (Peroxide) and Why Do We Use It?
Developer, often referred to as peroxide, is the liquid that activates hair colour. It contains hydrogen peroxide, which opens the hair cuticle and allows colour pigments to penetrate. The strength of the developer determines how much the hair cuticle opens and how much natural pigment is lifted or lightened.
- 10 Vol (3%) – Deposits colour only, minimal lift. Great for toning or darkening.
- 20 Vol (6%) – Standard strength for grey coverage and permanent colour. Provides up to 1–2 levels of lift.
- 30 Vol (9%) – Used for stronger lift, up to 3 levels. Common in lightening services.
- 40 Vol (12%) – Maximum lift, up to 4 levels. Typically used with high-lift blondes or bleach.
Choosing the right developer strength is just as important as choosing the right shade. Too strong, and you risk damage; too weak, and the colour may not process properly.
Why Do Mix Ratios Matter?
Every professional colour brand specifies a recommended ratio of colour to developer. This ensures the formula processes correctly, the pigments develop as intended, and the hair remains in good condition. Common ratios include:
- 1:1 – Equal parts colour and developer. Often used for permanent colour and grey coverage.
- 1:1.5 – One part colour to one and a half parts developer. Provides smoother consistency and easier application.
- 1:2 – One part colour to two parts developer. Common for toners, glosses, and lighteners.
Mixing incorrectly can lead to uneven coverage, unexpected tones, wasted product, or even hair damage. That’s why precision is key.
Tips for Accurate Mixing
- Always measure using a proper colour bowl or digital scale for accuracy.
- Stick to the same unit (ml or g) for both colour and developer.
- Follow the manufacturer’s instructions for processing times and ratios.
- Mix thoroughly until the texture is smooth and creamy.
- Record your successful formulas for client consistency.
Who Should Use This Calculator?
- Hairdressers – Save time and ensure consistent results across clients.
- Barbers – Perfect for beard tints and grey blending services.
- Apprentices – Learn correct mixing habits from the start.
- Mobile stylists – Work quickly and confidently without extra tools.
Final Thoughts
Hair colouring is both an art and a science. While creativity drives the artistry, precision in mixing ensures your vision comes to life. By using our Hair Colour Mix Ratio Calculator, you’ll never have to worry about incorrect ratios again—just flawless, professional results every time.