Hair dye guide
Developer volume is the one thing most DIY colorers get wrong — and it can make the difference between a gorgeous result and a damaged, patchy disaster. Here's a plain-English breakdown of what each developer volume does, when to use it, and when to stay away from it.
Developer (also called oxidant or peroxide) is the activating liquid you mix with hair dye or bleach. Without it, permanent hair color simply sits on the surface of your hair and washes out immediately.
The volume number refers to the concentration of hydrogen peroxide. 10 volume = 3% peroxide. 20 volume = 6% peroxide. 30 volume = 9% peroxide. 40 volume = 12% peroxide. The higher the volume, the more the hair cuticle opens — and the more the hair can be lightened.
Critically: more volume does not mean more vibrant color. It means more lift. Using a higher volume than necessary actually dilutes the pigment, giving you a lighter, washed-out result with more damage. Always use the lowest volume that achieves your goal.
| Goal | Best developer | Notes |
|---|---|---|
| Going darker / same level | 10 Volume | Deposit only — no lift needed |
| Toning / refreshing color | 10 Volume | Demi-permanent toners use 10 vol |
| Gray coverage | 20 Volume | 20 vol opens cuticle enough for full coverage |
| Lifting 1–2 levels | 20 Volume | Standard for most permanent applications |
| Lifting 2–3 levels | 30 Volume | Virgin hair only — not for previously colored |
| Lifting 3–4 levels | 40 Volume | Professional use only — very damaging |
| Bleaching (any amount of lift) | 20–40 Volume | 20 for scalp bleach, 30–40 for off-scalp only |
| Damaged or chemically treated hair | 10–20 Volume | Go one level lower than you normally would |
⚠️ Important: hair dye cannot lift through previously colored hair
If your hair has been permanently dyed before, hair dye — regardless of developer volume — cannot lighten it significantly. The artificial pigment in the hair shaft doesn't respond to developer the way natural pigment does. If you want to go lighter than your current dyed color, you need bleach first. No amount of high-volume developer will fix this.
Bleach works differently from hair dye — it contains no pigment, only the lightening agent. The developer volume controls how fast and how aggressively the bleach lifts color.
Yes — always factor in your hair's current condition before choosing a developer volume.
Virgin hair (never colored or bleached) is the most resilient and can handle higher volumes appropriately. Previously colored hair should drop down one volume level from what virgin hair would need for the same goal. Already bleached or damaged hair should use the lowest volume possible — ideally 10 volume — to avoid breakage and over-processing.
The golden rule: use the lowest volume that achieves your goal
Higher developer = more damage, not better results. A 20 vol developer gives you the same color deposit as 40 vol when going darker — but with a fraction of the damage. Always go as low as your goal allows.
Check your processing every 10 minutes. Hair continues to process even after you think it's done. Remove when you reach the desired level — extra time adds damage, not extra lift.
Not sure which developer volume is right for your specific starting color, target color, and hair condition?
Use the free developer volume guide →Most permanent box dyes include a 20 volume developer pre-measured for the amount of color in the box. This is correct for most standard applications. Do not add extra developer to box dye — it dilutes the color and changes the chemical ratio the manufacturer calculated.
Too low: the color won't lift enough — you'll get a darker result than intended, poor gray coverage, or no visible change if you needed lift. Too high: the color will be lighter than intended, pigment will be diluted, and your hair will experience more damage than necessary. In extreme cases (40 vol left on too long), it can cause scalp burns and significant breakage.
For permanent color with 20 volume developer, the standard processing time is 30–45 minutes. With 30 volume, check at 35 minutes. With bleach, check every 10 minutes and remove as soon as you reach the desired lift — never exceed 50 minutes with bleach regardless of the developer volume used.
Yes — mixing equal parts of two volumes gives you an average. For example, mixing 20 vol and 30 vol in equal parts gives approximately 25 vol. This is sometimes done by professionals to fine-tune lift level. Our developer volume calculator can help you find the right starting point for your goal.