Hair Dye to Developer Ratio: How Much to Mix
Work out how much hair colour and developer to mix at 1:1, 1:1.5 or 1:2 — by total, by the tube you have or by hair length — and which volume to use.
3 min read ·
Most permanent hair colours mix at 1 part colour to 1 part developer (1:1); many high-lift blondes, toners and bleaches use 1:2. So one 60 ml tube of colour needs 60 ml of developer at 1:1, or 120 ml at 1:2. To get the exact amounts — and how many tubes to buy for your hair length — use the Hair Dye Mixing Calculator. Always check the ratio printed on your product first: it's the authority.
Use the calculator
- Open the Hair Dye Mixing Calculator.
- Choose how to work it out:
- By total amount — you want, say, 180 ml of mixture. At 1:2 that's 60 ml of colour and 120 ml of developer.
- By colour you have — you have one 60 ml tube and need to know how much developer. At 1:1 it's 60 ml; at 1:2 it's 120 ml.
- By hair length — pick your length and thickness, and the calculator estimates how much colour you'll need, then the developer and the number of tubes.
- Set the ratio from your product's instructions.
- Read the amounts and how many tubes to buy, so you don't run out halfway.
Common mixing ratios
| Ratio | Typically used for |
|---|---|
| 1 : 1 | Most permanent cream colours, and many demi-permanents |
| 1 : 1.5 | Some permanent lines, and many lightening powders |
| 1 : 2 | High-lift blondes, toners, most bleach |
| 1 : 2.5 | Some high-lift and balayage powders |
| 1 : 3 | A few lighteners and pastel toners |
Ratios differ between brands and even between product lines from one brand.
Which developer strength?
| Developer | Lift | Use it for |
|---|---|---|
| 10 vol (3%) | No lift | Depositing tone, going darker, toners, demi-permanent |
| 20 vol (6%) | 1–2 levels | Grey coverage and same-level colour — the usual choice |
| 30 vol (9%) | 2–3 levels | Lifting, and off-scalp highlights |
| 40 vol (12%) | 3–4 levels | High-lift only, and only off the scalp |
Higher volume isn't "stronger colour" — it means more lightening and more potential damage and irritation. Use the lowest volume that does the job.
How much dye do you need?
The usual rule of thumb: one 60 ml tube for average shoulder-length hair. Short hair needs less; long or thick hair needs more; a root touch-up needs about half a tube. Thick or coarse hair takes noticeably more than fine hair of the same length. Porosity, how you section, and how generously you apply all change the real amount, so allow a margin — running out mid-application leaves uneven colour.
What happens if the ratio is wrong?
- Too much developer: the colour is weak, runny and fades fast, and coverage of grey suffers.
- Too little developer: the mixture is thick, doesn't process properly and may not lift or cover evenly.
Measure rather than eyeballing it — at 1:1.5 and 1:2 a small error moves the ratio a long way.
Mixing and safety tips
- Patch test 48 hours ahead, every time, even with a colour you've used before.
- Mix in a non-metallic bowl — metal can react with peroxide.
- Mix only what you'll use. The reaction starts as soon as colour and developer meet, and leftover mixture can't be saved.
- Wear gloves and work in a ventilated room.
- See a stylist for big changes: heavy lightening, colour correction, or colouring over previously treated hair.
The calculator handles the arithmetic only; it isn't a substitute for the product's instructions or professional advice.
Mixing paint instead?
For paints and pigments rather than hair dye, the Paint Color Mixing Calculator works out what colour two paints make and how much to measure.
Frequently asked questions
Can I use 20 vol for everything?
20 vol is the usual choice for grey coverage and same-level colour, but toners and deposit-only colours often call for 10 vol, and lightening needs more. Follow the product.
Is anything I enter stored?
No. The calculator runs in your browser.
Can I mix two shades of colour?
Yes — add the amounts of both colours together as your total colour, then apply the ratio to that total.