At some suggest or another, most hair colour technicians will must mix together a pair of various developers in order acquire the perfect volume that they need.

You are watching: Can i mix 20 and 30 volume developer


For example, you most likely will not have 25 volume sit around, for this reason naturally, you will certainly mix half of 20 volume and fifty percent of 30 volume in stimulate to make 25 volume.

And say you need to make 20 volume, yet you only have actually 40 volume lying around. Girlfriend would normally mix 1 ounce of 40 volume and also 1 oz of cream conditioner (or some other neutral mixture) to acquire a equipment that averages the end to 20 volume.

This is pretty straight forward and something you’re most likely used come doing in the shop anyways.


On her Ontario Hairstylist license exam, you could get a concern that looks something choose this:

Which that the complying with combinations would develop 30 volume developer?

20 + 10 + 20 50 + 20 + 20 10 + 40 + 20 40 + 40 + 20

Pretty confound if you’ve never also seen 50 volume and if did you do it never had to mix developer this way.

So, this is a formula I’ve arisen that you deserve to use to handle a question favor this on your hair license exam:

(X1 + X2 + X3 + …) / Y = Z

Where X1 , X2 , X3….. represent 1 oz of any volume the developer

Y to represent the total number of ounces of developer

Z represents the final volume of the resulting developer

So based on this formula, the exactly answer come the question above is B.


In the concern above, assume the each number you watch represents 1 oz (ounce) that developer, so that there room 3 equal parts of 3 different developers.

Since you need 30 volume, and also there space 3 ounces of developer in each of the feasible answers, it way that the complete volume of all of those 3 ounces merged when added together have to equal come 30 once it is split into 3 equal parts.

What separated by 3 will certainly equal to 30?....let’s execute some reverse math à 3 x 30 = 90.

Therefore, the correct answer in the question over must add up to 90 because 90 ÷ 3 = 30.

Only alternative B in the answer above adds approximately 90. 50 volume + 20 volume + 20 volume = 90 volume.

90 volume ÷ into 3 equal components = 30 volume.

We are merely averaging out the level that the volume when 3 equal portions of various volumes space combined.

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Another Example:

You ran the end of 20 volume and also you only have actually 40 and also 10 volume available. How can you develop 20 volume?

You must mix:

 1 component 40 + 1 component 10 + 1 part 10


 (40 + 10 + 10) ÷ 3 = 20

Makes sense, right?


Well, i hope I have actually simplified what may have actually initially seemed like a tricky or confusing test question.