Bleach Dilution Calculator

How to Dilute Bleach for Disinfection

Bleach is a powerful disinfectant that kills bacteria, viruses, and mold when diluted to the correct concentration. The proper bleach-to-water ratio depends on your specific use case. Using too little bleach may not effectively disinfect, while using too much can create harmful fumes and damage surfaces.

The Centers for Disease Control and Prevention (CDC) provides guidelines for bleach dilution ratios for different applications. Our bleach dilution calculator uses the standard formula to determine the exact amount of bleach needed for your desired concentration and volume.

Bleach Dilution Formula

The calculation uses the following formula:

$$V_{bleach} = \frac{C_{desired} \times V_{total} \times 0.00105 \times 100}{C_{bleach}}$$

where $V_{bleach}$ is the volume of bleach needed (mL), $C_{desired}$ is the desired chlorine concentration (ppm or mg/L), $V_{total}$ is the desired total volume (L), and $C_{bleach}$ is the bleach concentration (%).

Common Bleach Dilution Ratios

Here are standard dilution ratios recommended by the CDC for different applications:

• Food Contact Surfaces: 1 tablespoon (15 mL) of bleach per gallon of water (approx. 200 ppm)
• Non-Food Contact Surfaces: 1 cup (240 mL) of bleach per 5 gallons of water (approx. 600 ppm)
• Mold Remediation: 1 cup (240 mL) of bleach per gallon of water (approx. 1800 ppm)
• Pool Maintenance: 3-6 ppm for regular treatment, up to 18 ppm for shock treatment

Safety Precautions

When working with bleach, always follow these safety guidelines:

• Never mix bleach with ammonia, vinegar, or other cleaning products as it produces toxic chlorine gas
• Always work in a well-ventilated area
• Wear protective gloves and eye protection
• Always add bleach to water, not water to bleach
• Use unscented bleach for disinfection purposes
• Check the expiration date - bleach loses effectiveness over time

For related dilution and disinfection tools, try the Alligation Calculator and the Log Reduction Calculator.