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Developer to color mix calculator

Enter the current level, target level and gray percentage. Get the exact ratio, developer volume and processing time.

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This calculator uses basic rules.
Blendsor analyzes 70+ variables.

Porosity, color history, hair condition, specific brand... The exact formula, not just guidance.

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Quick guide: how to mix developer and hair color correctly

Why the correct ratio matters

The ratio between color and developer determines the final result: color deposit, lift, and durability. An incorrect ratio can result in dull colors, unnecessary damage, or insufficient gray coverage.

The volume rule

10vol (3%) deposits color without lift. 20vol (6%) is standard for 1-2 levels of lift and gray coverage. 30vol (9%) lifts 2-3 levels, ideal for highlights. 40vol (12%) provides maximum lift, for experienced professionals only.

Gray factor: how it affects the mix

The percentage of gray hair changes the formula. With few grays (<25%), color works normally. With moderate grays (25-50%), adding a natural base is recommended. With heavy grays (>50%), mixing a natural base with the desired tone ensures coverage and correct reflect.

Quick volume reference table

Volume Concentration Lift Primary use
10vol 3% 0 levels Toner, deposit, gray coverage
20vol 6% 1-2 levels Standard permanent color
30vol 9% 2-3 levels Highlights, balayage
40vol 12% 3-4 levels Maximum lift

For more information, check our complete guide to developer volumes and the article on professional gray hair coverage. Not sure how much product to mix? Calculate the exact amount of color and developer.

We answer your questions

Frequently Asked Questions

Everything you need to know before getting started

The most common ratio is 1:1 (equal parts). However, some products like bleach use 1:1.5 or 1:2. Always check the manufacturer instructions for your specific brand.
For gray coverage, 20 volume (6%) developer is recommended. With less than 50% gray, 20vol is sufficient. With more than 50%, some professionals mix with a natural base for better pigment deposit.
Yes, this is a common professional technique. For example, mixing 20vol with 30vol in equal parts gives you approximately 25vol. This is useful when you need intermediate lifting power.
Standard processing time is 30-45 minutes for permanent color, 15-25 minutes for toner/demi-permanent, and 35-50 minutes for lightening processes. Never exceed the manufacturer recommended time.
Using a higher volume developer than necessary can cause excessive hair damage, lighter results than expected, and poor gray coverage (color processes too quickly and does not deposit well).
Yes. While 1:1 is standard for most brands (Wella, Schwarzkopf, L'Oreal), some specific lines may require 1:1.5 or 1:2. Always check the product technical sheet.

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