Finish Your Walls with Precision

Paint Coverage: The Math Behind the Gallons

Paint coverage is not an exact science. It depends on the porosity of the surface, the color you are applying, and the quality of the paint. However, the industry standard is that 1 gallon of paint covers roughly 350 square feet in a single coat.

In the UK and Australia, paint is sold in liters. The standard coverage is roughly 12 to 14 square meters per liter for a single coat. Our Paint Coverage Calculator allows you to toggle between US gallons and metric liters.

Why Do You Need Two Coats?

A single coat of paint is rarely enough. The first coat is absorbed by the porous surface (drywall, wood, or masonry). The second coat provides the actual color, durability, and washability.

If you are painting a dark color over a light color (or vice versa), you may need a tinted primer plus two topcoats. Our tool automatically calculates for two coats, but you can adjust the coat count for your specific project.

Understanding Sheen Levels

Paint is not just about color; it is also about finish. The "sheen" determines how much light reflects off the surface and how easy it is to clean. Choosing the wrong sheen can ruin the look of a room.

• Flat / Matte: No reflection. Hides imperfections well. Ideal for ceilings, low-traffic areas, and adult bedrooms. Difficult to clean.
• Eggshell: A subtle, soft sheen. The most popular choice for living rooms and hallways. Offers a good balance of durability and aesthetic.
• Satin: A pearl-like finish. Highly durable and washable. Ideal for kitchens, bathrooms, and high-traffic hallways.
• Semi-Gloss / Gloss: High reflection. Very durable and easy to clean. Best for trim, doors, cabinets, and high-moisture areas. Highlights surface imperfections.

For exterior paint, satin or semi-gloss is often used to resist moisture and UV rays. For interior trim, semi-gloss is the standard choice.

The Critical Role of Primer

Primer is often skipped by DIYers, which is a costly mistake. Primer is a preparatory coating that seals the surface and provides a strong bond for the topcoat.

You must use a primer if:

• You are painting new drywall (which is highly porous).
• You are painting over a dark color with a light paint.
• You are painting over glossy surfaces (which need sanding and a bonding primer).
• You are painting over stained wood or water-damaged areas (use a stain-blocking primer).

For new drywall, use a PVA primer. For walls with stains or smoke damage, use a shellac-based primer (like BIN). For exterior wood, use an oil-based or water-based wood primer.

Global Paint Standards: US vs. UK vs. Australia

While paint is universal, the measurements, terminology, and VOC regulations vary significantly.

USA: Paint is sold in gallons (1 gal = 3.78L). VOC regulations vary by state (California has the strictest limits). Behr, Sherwin-Williams, and Benjamin Moore are the leading brands.

UK: Paint is sold in liters (2.5L, 5L, 10L). All paints sold in the UK must comply with EU VOC limits. Dulux and Crown are the dominant brands.

Australia: Paint is sold in liters. The APAS (Australian Paint Approval Scheme) certifies low-VOC and environmentally friendly paints. Taubmans and Wattyl are popular brands.