What is a bleach bath?

A bleach bath (also called a bleach wash or soap cap) mixes bleach powder, developer and shampoo together. The shampoo dilutes the bleach, making it gentler and easier to apply evenly through the hair. It is used for subtle lightening, toner removal and evening out patchy colour.

What ratio should a bleach bath be?

The standard ratio is 1:1:1 — equal parts bleach powder, developer and shampoo. For gentler results, use 1:1:2 (more shampoo). For slightly stronger lift, use 1:1:0.5 (less shampoo). The shampoo also helps the mixture spread easily through the hair.

How long should I leave a bleach bath on?

Never exceed 20 minutes. Most bleach baths achieve their result within 10-15 minutes. Check the hair every 5 minutes. The mixture loses strength faster than straight bleach because of the shampoo dilution. Rinse as soon as you see the target lift.

When should I use a bleach bath instead of straight bleach?

Use a bleach bath for subtle changes: removing old toner, evening out colour, lifting 1-2 levels, or gently fading semi-permanent colour. Use straight bleach when you need significant lightening (3+ levels). Bleach baths are excellent for colour corrections where gentleness matters.

CutCalcs

Bleach Bath Calculator — Gentle Lightening Mix Ratios

Calculate bleach bath mix ratios (bleach, developer, shampoo) for gentle lightening.

Hair Length

Determines total mix quantity needed

Target Lift

How many levels lighter you want to go

Developer Volume

Higher volume gives more lift but more damage

Bleach Parts

Bleach powder ratio part

Developer Parts

Developer ratio part

Shampoo Parts

Shampoo ratio part

How We Calculate This

Mix Ratios

Each component = Total mix x (Part ratio / Sum of all parts)

The total mix volume is based on hair length. The ratio determines how much of each component makes up the mix. Standard is 1:1:1 (bleach : developer : shampoo). More shampoo makes a gentler mix with less lift.

Frequently Asked Questions

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Work out the correct developer-to-colour ratio for different application types.

Toner Mix Calculator

Calculate toner and developer quantities for post-bleach toning services.

Bleach Mix Calculator

Determine the right bleach powder to developer ratio and total quantity needed.

Colour Correction Calculator

Estimate colour correction steps, products and processing time needed.

Last updated: March 2026

All calculations are estimates. Always perform a strand test before chemical services.