Hair Developer Ratio Calculator
By using our calculators, you agree to our Terms of Use.
Mix the right developer amount from your color weight and chosen ratio — see total bowl weight instantly.
Rates last reviewed: July 2026
Mix amounts
Developer needed
90 g
Total bowl weight: 150 g
- Color
- 60 g
- Ratio
- 1:1.5
- Total bowl
- 150 g
Related calculators
Hair color mixing ratios
Hair color and lightener are mixed with developer (peroxide) at ratios printed on the product label — commonly 1:1, 1:1.5, or 1:2 (color to developer). The first number is color; the second is developer. At 1:1.5 with 60 g of color, developer = 60 × 1.5 = 90 g and total bowl weight = 150 g. Ratios are by weight (grams), not volume, unless the manufacturer specifies otherwise.
Different lines and levels use different ratios. Permanent color often mixes 1:1; high-lift or certain blonding powders may use 1:2 for more lift and liquidity. Always follow the brand instructions for the specific shade and developer volume (10, 20, 30, 40 vol). This calculator does the math only — it does not replace the label or your training.
Example: 45 g color at 1:2 → developer = 45 × 2 = 90 g, total = 135 g. Weigh color and developer on a scale for consistency; “squirt” measuring drifts over time and wastes product. Record what you use per service to improve salon pricing estimates.
Common questions
Should I follow this calculator or the product label?
Always follow the manufacturer label and your education for the specific color line, shade, and developer volume. Ratios vary by brand and product type — use this tool to check your math, not to override instructions.
Do I need a strand test?
Yes for new formulas, lift goals, or compromised hair. A strand test shows lift, tone, and timing on actual hair before a full application. This calculator only computes mix weights — it does not predict processing results.
Are ratios by weight or volume?
Professional mixing is usually by weight (grams on a scale). Some retail kits use volume. When in doubt, use grams and the ratio on your technical guide.