Soft Wash Mix Calculator
Calculate sodium hypochlorite, water, and surfactant amounts from your batch size, starting SH strength, and desired soft wash mix percentage.
Formula
SH amount equals desired percentage divided by starting percentage, multiplied by batch size. Water amount equals batch size minus SH amount. Surfactant amount equals batch size multiplied by surfactant amount per unit.
Example calculation
For a 20 gallon batch using 12.5% starting SH and a 3% desired final mix, SH amount is 4.8 gallons and water amount is 15.2 gallons before surfactant.
Common mix warnings
Do not use a desired percentage higher than your starting SH percentage. Do not treat calculator math as safety guidance. Always verify labels, PPE, ventilation, storage, surface risk, and local rules before handling chemicals.
SH batch mix calculator: what the result means
This tool estimates a batch of sodium hypochlorite (SH) and water. It uses the starting concentration and your chosen target; it does not choose a suitable concentration for a surface or account for an injector's draw ratio.
Does batch size include the surfactant?
No. The SH and water amounts add up to the entered batch size. Surfactant is calculated separately and added on top, so the total volume is larger and the resulting SH percentage is lower. The displayed target applies before surfactant is added.
Is this an X-Jet or downstream injector calculator?
No. It calculates the mixture in the batch, not the concentration delivered after equipment adds more water. An injector ratio requires a separate calculation based on the actual equipment setup.
How do I check the arithmetic?
For the example of 20 gallons, 12.5% starting SH and a 3% target, 20 × 3 ÷ 12.5 = 4.8 gallons of SH. The water amount is 20 − 4.8 = 15.2 gallons. These are arithmetic examples, not recommended application strengths or product doses.
Related calculators
After estimating mix amounts, use the pricing and profit calculators to include materials, labor, overhead, and margin in the quote.
Pressure Washing Pricing Guides
Use these guides to connect soft wash mix math to quote pricing and profit checks.
Safety disclaimer
This calculator is for math convenience only. It is not chemical safety training. Users must follow chemical labels, manufacturer instructions, PPE requirements, local laws, and professional safety practices. Do not mix chemicals unless you understand the risks and proper handling requirements.
Build quotes around your mix costs
Pair this mix calculator with pressure washing pricing and profit tools. The full downloadable pressure washing kit is available now.