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DilutionCalculator
Disinfection, Cleaning & Household

Disinfectant Dilution Calculator

Mix a disinfectant the way the label says.

Standard Reference EPA Standard Protocol
Presets:
Formula: C₁ × V₁ = C₂ × V₂
V₁ = (C₂ × V₂) / C₁
Stock Source
Calculating
Target Conc
Final Volume
Fluid color:
Dilution Factor (DF)
5.00×
1 : 5 dilution
Solvent (Buffer / Water)
40.00 mL
V₂ - V₁ volume

Disinfectant Dilution Calculator: Live Flask Simulation

Live color sync
Transfer 10 mL aliquot
Stock Solution (C₁)
75%50%25%
10 mM
Concentration (C₁)
Aliquot to draw: 10 mL
Final Dilution (C₂)
CALIBRATION MARK (V₂)
2 mM
Concentration (C₂)
Total Volume: 50 mL
Color depth (Beer-Lambert) Relative Intensity: 20% (Absorbance Factor: 0.200)

Step-by-Step Bench Protocol

1

Pipette Stock Aliquot

Draw 10 mL of stock (10 mM) with a pipette.

2

Add Diluent / Buffer

Add 40 mL of water or buffer to reach the final mark.

3

Invert and Mix

Invert the tube to mix. You now have 50 mL at 2 mM (a 5× dilution).

How It Works

This calculator works in 4 steps.

  1. Enter the label rate

    Type the ratio or the oz per gallon for the claim being used.

  2. Enter the contact time

    Type the wet contact time from the same label claim.

  3. Enter the container size

    Type the volume of the bottle, bucket, or dispenser.

  4. Read the amounts

    The calculator returns concentrate and water amounts with the contact time reminder.

The Formula

The formula scales the label rate to the container volume.

From oz per gallon V_conc = (oz/gal) × gallons
From ratio 1:X oz/gal = 128 / X
Metric form mL per L = 1,000 / X
X:
Ratio term on the label
oz/gal:
US fluid ounces per US gallon
Worked example

A quaternary ammonium disinfectant labeled 1:64 (2 fl oz per gallon) needs 6 fl oz (177 mL) for a 3-gallon bucket.

Conversion Table

The conversion table converts 5 common label ratios into amounts per US gallon and per liter.

Label ratioPer US gallon (fl oz)Per US gallon (mL)Per 1 L (mL)
1:324 fl oz118.3 mL31.25 mL
1:642 fl oz59.15 mL15.62 mL
1:1281 fl oz29.57 mL7.812 mL
1:2560.5 fl oz14.79 mL3.906 mL
1:5120.25 fl oz7.393 mL1.953 mL

128 US fl oz = 1 US gallon. Use the rate printed on the product label.

What Is the Disinfectant Dilution Calculator?

The Disinfectant Dilution Calculator is a tool that applies the directions on a registered disinfectant's label, such as 2 fl oz per gallon (1:64), to the user's container size. The calculator scales the label rate; it does not create new rates.

In the United States, the Environmental Protection Agency (EPA) registers disinfectants, and the label lists the dilution, contact time, and surfaces for each claim. A rate below the label rate may not meet the claim, and a rate above it may damage surfaces or exceed residue limits. The calculator asks for the label rate and the claim's contact time and prints both on the result.

Common Uses

There are 5 main uses of this calculator.

  • Healthcare surfaces

    Environmental services teams mix label-rate disinfectants.

  • Schools

    Custodians scale label rates to classroom buckets.

  • Food service

    Kitchens apply food-contact sanitizer rates.

  • Veterinary clinics

    Staff mix kennel disinfectants per the label.

  • Gyms and fitness centers

    Staff fill spray bottles at label rate.

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