# Deck Stain Calculator: How Much Stain Do I Need?

If you’re building a deck, you can stain the boards before or after installation, depending on your preferences. Use our deck stain calculator to determine how much stain you need based on your deck’s square footage.

## How to Estimate the Amount of Stain You Need for Your Deck

Enter the length and width of the deck, as well as the number of coats to calculate the amount of stain needed:

The two factors that influence the amount of stain you need are the total square footage of the deck and how many coats of stain you’ll apply. Depending on your chosen product, a deck will require 1-2 coats of stain. Refer to the manufacturer’s instructions for specific directions.

A typical gallon of deck stain-and-sealer covers about 175 square feet and only needs one coat. A gallon of stain that requires two coats will cover about 88 square feet.

Here’s an example of how much stain for a 20×20 deck:

First, we’ll find the square footage of the deck by multiplying the length by the width in feet. A 20 x 20 deck measures 400 square feet. Then, we can determine how many gallons of stain to use.

You’ll need 3 gallons to cover 400 square feet with a one-coat stain product. For a two-coat stain, you’ll need 5 gallons.

Here’s an example of how much stain for a 12 x 12 deck:

First, we’ll find the square footage – 12 x 12 = 144 square feet. Since one gallon of one-coat stain and sealer covers 175 square feet, you’ll only need one gallon. You’ll need two gallons of stain if you opt for a stain that requires two coats.

## Frequently Asked Questions (FAQ)FAQ

### What kind of brush should you use for deck stain?

It’s best to use a natural bristle brush for deck stain. If covering a large area, you can also use a paint roller. A roller can help you achieve a more cohesive look, but you may need a brush to reach into cracks.

### How many square feet do five gallons of deck stain cover?

Five gallons of a one-coat deck stain and sealer covers 875 square feet. Five gallons of two-coat deck stain covers 440 square feet.

### Can you stain a deck in the summer?

You should avoid staining a deck during hot and humid times of the year since it can affect how the stain dries. Instead, try spring or fall when the weather is moderate.

### How much does professional deck staining cost?

If you want to pay a professional to stain your deck, the average costs are about \$4 per square foot. The pricing will depend on location. Expect to pay about \$1,600 for a 400-square-foot deck at this rate.