How Much QDS Do You Need? A Practical Guide + Easy Calculator

When you're planning a decontamination project, one of the most common questions is: “How much QDS should I use?” The good news is that Quick Decon Solutions (QDS) makes the math simple with the calculators below.

Whether you're treating a full containment area or mixing a small batch for touch‑up work, this guide walks you through exactly how much prod

uct you need—and how to scale it up or down with confidence.

Coverage Rate: 1 Gallon Treats 400 Square Feet

A single gallon of mixed QDS solution will effectively treat 400 sq ft of surface area. This is your baseline for calculating how much product to prepare.

Can You Mix Less Than a Full Gallon? Absolutely.

You don’t need to use a full 1‑gallon packet every time. If you want to mix a smaller batch, simply scale the powder and water proportionally.

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Basic Formula

Mixing Ratio: 24.2 Grams of QDS Powder per 1 Gallon of Water

Each gallon of QDS solution requires:

• 24.2 grams of QDS powder

• 1 gallon of deionized (DI) water

This ratio is precise and ensures optimal performance.

QDS Usage Calculator

Below is a simple calculator you can embed or convert into a webpage widget.

1. Calculate How Much QDS Solution You Need

Input: Total square footage Output: Gallons of QDS solution required + grams of powder

Formula

• Gallons required = Total sq ft ÷ 400

• Powder required (grams) = Gallons × 24.2

Example

If you need to treat 1,200 sq ft:

• Gallons = 1200 ÷ 400 = 3 gallons

• Powder = 3 × 24.2 = 72.6 grams

2. Mix a Custom Batch (Any Size)

If you only want to mix a partial gallon:

Desired Solution	Powder Needed	Water Needed
1 gallon	24.2 g	1 gallon
½ gallon	12.1 g	0.5 gallon
¼ gallon	6.05 g	0.25 gallon
1 liter	6.39 g	1 liter
500 mL	3.20 g	500 mL

(Conversions based on 1 gallon = 3.785 liters)

Quick Reference Chart

Area to Treat (sq ft)	Gallons of QDS	Powder Needed (grams)
200 sq ft	0.5 gal	12.1 g
400 sq ft	1 gal	24.2 g
800 sq ft	2 gal	48.4 g
1,200 sq ft	3 gal	72.6 g
2,000 sq ft	5 gal	121 g

Final Thoughts

QDS is designed to be flexible—mix a full gallon for large‑scale decon work or scale down to a small batch for spot cleaning. With the simple formulas above, you can calculate exactly what you need every time.