This calculator helps you quickly work out how much developer to mix with one or two hair color shades. It focuses on simple weight ratios so you can repeat formulas accurately and avoid guessing in the bowl.
For best accuracy, always measure by weight in grams. Volume measures like teaspoons or tablespoons are less reliable, especially when products have different densities.
The calculator is based on straightforward proportional mixing. It assumes that your chosen mixing ratio (for example, 1:1 or 1:2) already follows your product manufacturerโs directions.
First, the calculator adds the two color amounts to find total color weight:
total_color = color1 + color2
Then it multiplies by the developer ratio you entered:
developer_amount = total_color ร developer_ratio
The final mixture is the sum of color and developer:
total_mix = total_color + developer_amount
In mathematical notation, if we call the first color c1, the second color c2, and the ratio r, the key relationships can be written as:
Where:
The tool simply automates these steps so you do not have to calculate them by hand each time.
After you click Calculate Mix, you will typically see:
Use the total mixture value as a rough guide to whether you have enough product for your hair length. Keep in mind that every head of hair is different, and some textures or densities need more product than others.
Approximate total mixture ranges many stylists use as a starting point are:
These are only general ranges. If you are unsure, it is often safer to mix a little more product than you think you need, especially for long or very thick hair, while still respecting the manufacturerโs maximum processing guidelines.
Imagine you want a custom brunette and decide to mix:
Step-by-step:
In the calculator you would enter:
The results let you know that you need 60 g of developer and will end up with 100 g of total mixture, which is typically enough for a solid root-to-end application on medium to longer hair, depending on thickness.
You can repeat this same process for single-color formulas by setting Dye Color 2 to 0 g. For example, 40 g of one color at a 1:1 ratio would need 40 g of developer, giving 80 g of total mixture.
Different developers and mixing ratios are used for different color goals. Always check your product instructions first, but this reference table can help you understand the typical uses of common combinations.
| Developer Volume | Typical Mixing Ratios | Common Use Cases | Notes |
|---|---|---|---|
| 10 vol | 1:1 or 1:1.5 | Gentle deposit, darkening, tone-on-tone, refreshing faded lengths | Minimal lift; often used for glosses or when you do not want to lighten the natural base. |
| 20 vol | 1:1 or 1:2 | Standard gray coverage, 1โ2 levels of lift with permanent color | Most common choice for permanent hair color on virgin hair or standard root retouches. |
| 30 vol | 1:1 or 1:2 | Stronger lift (up to around 3 levels) with high-lift or permanent color | More aggressive; typically reserved for specific lightening situations and resistant hair. |
| 40 vol | Varies by product | High-lift tints and some lighteners only, where specifically allowed | High risk of damage if misused. Strictly follow product guidelines; often best left to professionals. |
| Demi-permanent developer (low vol) | 1:1 or per brand | Blending gray, refreshing color, subtle tonal changes | Usually a low-volume or dedicated activator designed for deposit-only color. |
Brands can recommend different developer volumes and ratios even for similar shades, so treat this table as general guidance only.
Use your hair length, density, and desired technique to estimate how much total mixture you need, then plug your chosen color amounts into the calculator. Some practical guidelines:
When in doubt, mix slightly more than calculated so you do not run out mid-application, as long as you do not exceed the amount recommended by the manufacturer for a single service.
To make maintenance easier:
The calculator only handles mixing amounts. For best application:
This calculator is designed as a weight-based ratio helper. It is not a full hair consultation and cannot predict your exact color result. Keep these important points in mind:
If you are planning a major color change (significant lightening, color corrections, or working on very compromised hair), consulting a professional stylist or colorist is strongly recommended.
This calculator is an educational tool to help with basic mixing math. It is not a substitute for professional training, personalized advice, or the safety instructions that come with your hair color products.
Developed with reference to standard salon mixing practices. For best results, pair this tool with up-to-date guidance from your product manufacturer or a licensed professional. Last updated: 2025.