US brick

A standard US brick measures 8 inches (203 mm) long, 3.625 inches (92 mm) wide, and 2.25 inches (57 mm) tall. This is the modular brick size most commonly used in US residential and commercial construction. This page covers the exact dimensions, how brick sizing accounts for mortar joints, and how US brick compares to the UK standard.

Dimensions

Nominal vs actual size

The 8 x 3.625 x 2.25 inch measurement above is the actual (also called “specified”) brick size. Bricklayers often refer to “nominal” dimensions instead, which add a standard 0.375 inch (9.5 mm) mortar joint to each measurement, making the nominal modular brick size 8 x 4 x 2.67 inches when laid in a wall with mortar joints.

Common US brick sizes

Modular brick is the most common size used in the US, sized to work cleanly with 4-inch and 8-inch increments common in construction planning. Utility brick, a larger format, is often chosen to reduce the total number of bricks and labor needed to cover a given wall area.

Weight

A standard US brick weighs approximately 4.5 to 5 pounds (2 to 2.3 kg), depending on the clay composition and firing process. This weight is a practical consideration for both structural load calculations and manual handling during construction.

Mortar joint standards

US masonry commonly uses a 3/8 inch (9.5 mm) mortar joint between bricks, which is factored into the nominal sizing system so that a specific number of bricks plus joints adds up to standard measurements like one foot or one yard, simplifying wall layout calculations for builders.

Frequently asked questions

What is the standard size of a US brick?

8 x 3.625 x 2.25 inches (203 x 92 x 57 mm) for the actual size, or roughly 8 x 4 x 2.67 inches nominal, including a standard mortar joint.

How much does a standard brick weigh?

About 4.5 to 5 pounds (2 to 2.3 kg), depending on the specific clay mixture and manufacturing process used.

What is the difference between nominal and actual brick size?

Actual size is the brick’s physical dimensions alone. Nominal size adds a standard mortar joint (typically 3/8 inch) to account for how bricks are spaced when laid in a wall.

Is a US brick the same size as a UK brick?

No. A UK brick measures 215 x 102.5 x 65 mm, larger in every dimension than the standard US brick at 203 x 92 x 57 mm.

How many bricks are needed per square foot of wall?

Using standard modular brick with typical mortar joints, about 6.75 bricks are needed per square foot of single-wythe wall, though this varies slightly based on the exact brick size and joint thickness used.

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