How much developer to add to hair color? Ratios in grams from 1:1 to 1:5
A 1:X ratio means X grams of developer for every gram of color. Developer = grams of color × X. For 40 g of color at 1:1.5, that's 40 × 1.5 = 60 g of developer, and the whole mix weighs 100 g.
Developer calculator
Chart: grams of developer for a given amount of color
| Color | 1:1 | 1:1.5 | 1:2 | 1:3 | 1:5 |
|---|---|---|---|---|---|
| 10 g | 10 g | 15 g | 20 g | 30 g | 50 g |
| 20 g | 20 g | 30 g | 40 g | 60 g | 100 g |
| 30 g | 30 g | 45 g | 60 g | 90 g | 150 g |
| 40 g | 40 g | 60 g | 80 g | 120 g | 200 g |
| 50 g | 50 g | 75 g | 100 g | 150 g | 250 g |
| 60 g | 60 g | 90 g | 120 g | 180 g | 300 g |
| 70 g | 70 g | 105 g | 140 g | 210 g | 350 g |
| 80 g | 80 g | 120 g | 160 g | 240 g | 400 g |
| 90 g | 90 g | 135 g | 180 g | 270 g | 450 g |
| 100 g | 100 g | 150 g | 200 g | 300 g | 500 g |
| 120 g | 120 g | 180 g | 240 g | 360 g | 600 g |
| 150 g | 150 g | 225 g | 300 g | 450 g | 750 g |
What 1:1.5 or 1+1.5 means
Both mean the same: the first number is the color, the second the developer. “1+2” on the box means 1:2, twice as much developer as color.
The ratio tells you nothing about the developer strength (3%, 6%, 9% or 12%, also sold as 10, 20, 30 or 40 volume). You choose the strength separately, based on the color's technical sheet and the result you're after.
A mix of several shades
Work out the developer from the total of all the colors in the bowl, not shade by shade.
30 g of 7.1 + 15 g of 8.0 = 45 g of color
45 g × 1.5 = 67.5 g of developer
whole mix: 45 g + 67.5 g = 112.5 g
If the bowl also has additives, such as pigments or boosters, check with the manufacturer whether they count as color for the ratio.
Poured too much developer? How to fix the ratio
Work out how much color the developer already in the bowl calls for, and add the difference.
color needed = developer in the bowl ÷ X
to add = color needed − color in the bowl
Example: the bowl has 45 g of color, the ratio is 1:1.5, and 75 g of developer went in instead of 67.5 g. 75 ÷ 1.5 = 50 g, so you're 5 g of color short.
With several shades, add the missing color in the same proportions as the bowl. For 30 g of 7.1 and 15 g of 8.0 (2:1), that's about 3.3 g of 7.1 and 1.7 g of 8.0.
Grams or milliliters?
This chart assumes you weigh. Some manufacturers give ratios in milliliters, and color and developer have different densities, so 60 ml doesn't always weigh 60 g. If the technical sheet gives milliliters and you work with a scale, ask the manufacturer or your supplier how to convert.
How Color Lab does it
With Color Lab there's nothing to work out by hand. Scan the developer, choose the ratio, and the app tells you how many grams to add to the color already weighed in the bowl.
Color in the bowl: 45.0 g
- 1:1
- 45.0
- 1:1.5
- 67.5
- 1:2
- 90.0
- 1:3
- 135.0
- 1:5
- 225.0
More about what the app records for every mix: the developer panel and formulas in Color Lab.
Always follow the color manufacturer's instructions for developer ratio and strength. This page shows how to work out the grams, not which ratio to use.
Questions
How much developer for 60 g of color?
At 1:1, 60 g; at 1:1.5, 90 g; at 1:2, 120 g; at 1:3, 180 g; and at 1:5, 300 g of developer.
What does a 1:2 ratio mean?
2 g of developer for every 1 g of color. 30 g of color needs 60 g of developer, and the whole mix weighs 90 g.
Is developer worked out from the whole mix?
No, from the color only: the total of all shades in the bowl. The whole mix is color plus developer.
How do I know which ratio to use?
Check the box or the color's technical sheet. The same brand can use different ratios for different lines, for example permanent color and a high-lift range.