Brick Course Height Calculator

What Is a Brick Course?

A brick course is one horizontal row of bricks laid on a bed of mortar. The course height, or gauge, is one brick height plus one bed joint. A modular brick is 2 1/4 in (57 mm) high, and a 3/8 in (9.5 mm) bed joint brings the course height to 2 5/8 in, or 2.625 in (66.7 mm).

Every brick wall rises in steps of one course. A window sill, a door head, a lintel and the top of the wall each land on one of those steps, or the bricklayer cuts bricks or changes the joints. The brick course height calculator works out where each step falls, so the wall height, the number of courses and the joint size agree before the first brick goes down.

The brick course height calculator has 5 parts:

• A mode switch chooses between wall height to courses and courses to wall height.
• A brick height input holds 11 presets, from modular, king and queen brick to UK, Australian, India and concrete block sizes, plus a custom height.
• A mortar joint thickness input sets the bed joint in inches or millimeters.
• A base setting counts or skips the mortar bed under the first course.
• A results panel and story pole show the course height, courses per foot, the wall height, the joint that hits a target height, and the height of every course.

How to Use the Brick Course Height Calculator

To use the brick course height calculator, follow 6 steps. Results update as you type.

1. Choose the mode. Height → courses finds the number of courses in a wall height. Courses → height finds the height of a number of courses.
2. Enter the target height or the number of courses. Heights run from the base to the top of the last brick, in inches or millimeters.
3. Pick the brick or block, or choose Custom height and type the actual brick height.
4. Set the bed joint, normally 3/8 in or 10 mm.
5. Set the base. Keep the mortar bed for brick laid on a footing; choose a dry base for brick that starts without a joint underneath.
6. Read the results and the story pole. The story pole lists the height to the top of every course.

In Height → courses mode the results give 4 answers: the exact number of courses, the nearest whole courses below and above the target, the height each one reaches, and the bed joint that lands each one on the target exactly.

Brick Course Height Formula

The brick course height formula is course height = brick height + bed joint, and the wall height is the number of courses times the course height.

The formula uses 3 values: h is the actual brick height, t is the bed joint thickness and N is the number of courses. A modular brick course is 2.25 + 0.375 = 2.625 in, so 10 courses rise 26.25 in (667 mm) and 1 ft of wall height holds 12 ÷ 2.625 = 4.57 courses. In metric, the same course is 66.7 mm, which gives 15.0 courses per meter.

Standard Brick Heights and Mortar Joints

The US modular and standard brick is 2 1/4 in (57 mm) high and gives a 2 5/8 in (66.7 mm) course with a 3/8 in bed joint. The table lists 10 common brick and block heights with the course height, the courses per foot and per meter, and the module each size fits.

Assumptions: 3/8 in (9.5 mm) bed joints for US units and 10 mm bed joints for UK, Australian and India brick.

BIA modular coursing. The Brick Industry Association (BIA) sizes modular brick in Technical Note 10 so whole courses land on a 4 in grid: 3 modular courses rise 8 in, which makes each course 2.667 in, not 2.625 in. Three 2 1/4 in bricks in 8 in leave 0.417 in for each bed joint, a little over 3/8 in. Metric modular work uses the same idea on a 100 mm grid, and the India modular brick lands on it with every course.

Brick dimensions beyond height. Course height uses the brick height only. Brick length and brick depth matter for the brick count and the head joints: a modular brick is 3 5/8 in deep, 2 1/4 in high and 7 5/8 in long, and a standard brick is the same except for its 8 in length. Three modular bricks end to end with two 3/8 in joints measure 23 5/8 in; add the third joint and the run is an even 24 in. To count the bricks in a wall, use the brick calculator.

India and UK bricks. Indian Standard IS 1077 covers the 190 × 90 × 90 mm modular brick and the 230 × 110 × 70 mm brick. The Brick Development Association gives the UK brick a co-ordinating size of 225 × 112.5 × 75 mm with a 10 mm joint, so each UK course is 75 mm and a 2.4 m wall takes exactly 32 courses. The Australian standard brick measures 230 × 110 × 76 mm and courses at 7 courses to 600 mm, so 7 courses of Australian brick stand 600 mm (23.6 in) with joints of about 9.7 mm, or 602 mm with full 10 mm joints.

Brick Coursing and Gauge Rod Layout

A story pole, called a gauge rod in the UK, is a straight length of timber marked with the top of every course. The bricklayer stands the story pole at each corner, runs a line between the marks, and lays every course to the line, which keeps courses level and the same height along the whole wall.

To mark a story pole, follow 4 steps:

1. Mark the datum, the top of the footing, slab or damp-proof course where the first course starts.
2. Mark the top of every course from the story pole table beside the calculator results.
3. Mark the fixed heights: window sills, door heads, lintels, floor levels and the wall top.
4. Check where each fixed height falls. A fixed height between 2 marks needs a joint adjustment over the courses below.

Set the brick coursing out before the footing is poured where possible. A footing height chosen in whole courses removes cut bricks at the bottom of the wall.

Adjusting Mortar Joint Thickness for Wall Height

To land a wall height on a whole course, change the bed joint thickness over the courses below the target, within the tolerance the specification allows. TMS 602, the US specification for masonry construction, lets bed joints vary by ±1/8 in (3 mm) from the specified size, so a 3/8 in bed joint can run from 1/4 in (6.4 mm) to 1/2 in (12.7 mm).

The calculator gives 2 joint options for every target height: the joint for the whole courses below and the joint for the whole courses above. A tick marks a joint inside ±1/8 in of the joint you entered. The table shows 6 common wall heights in modular brick with a mortar bed under the first course.

Heights in multiples of 8 in, such as 4, 6, 8 and 10 ft, land on whole courses with a 0.417 in joint: the BIA module. A 3 ft wall at 13 courses needs a 0.519 in joint, outside the 1/2 in limit, so 14 courses at 0.321 in is the better choice.

Spread the change across every course below the target. Changing one or two joints by a large amount shows as a band in the finished wall.

Brick Course Height Calculation Examples

Modular brick with 3/8 in bed joints and a mortar bed under the first course gives 7 courses at 18 3/8 in (467 mm) and 27 courses at 5 ft 10 7/8 in (1,800 mm). The brick coursing height chart lists 9 common course counts in 3 systems.

On a dry base, take one bed joint off each figure: 3/8 in (9.5 mm) for US brick and 10 mm for UK brick. The 4 worked examples below use the calculator settings in brackets.

1. 8 ft modular wall (Height → courses, 96 in). 96 ÷ 2.625 = 36.57 courses. 36 courses reach 7 ft 10 1/2 in and 37 courses reach 8 ft 1 1/8 in. A 0.417 in joint lands 36 courses on 8 ft exactly.
2. UK garden wall (Height → courses, 2,400 mm, UK brick). 2,400 ÷ 75 = 32 courses with no adjustment.
3. India 70 mm brick, 3 m wall (Height → courses, 3,000 mm, India 70 mm). 3,000 ÷ 80 = 37.5 courses. 37 courses reach 2,960 mm with 10 mm joints, and 11.1 mm joints lift them to 3,000 mm. 38 courses land on 3,000 mm with 8.9 mm joints.
4. 40 courses of modular brick (Courses → height, 40). 40 × 2.625 = 105 in, or 8 ft 9 in (2,667 mm), with a mortar bed under the first course, and 104 5/8 in on a dry base.

Common Brick Coursing Mistakes

There are 6 common brick coursing mistakes, and each one shows up as a cut course, a wavy line or a sill that misses its mark:

1. Using the nominal brick height. A modular brick is 2 2/3 in nominal and 2 1/4 in actual. The course height formula needs the actual brick height plus the bed joint.
2. Mixing a BIA chart with a 3/8 in joint. BIA modular coursing reads 2.667 in per course. Laid at 2.625 in, the wall falls 1/2 in behind at 12 courses and 1 1/4 in behind at 30 courses.
3. Forgetting the mortar bed under the first course. The first course on a footing sits on a joint. Leaving that joint out, or counting it on a dry base, puts every mark one joint off.
4. Marking from the wrong datum. Measure from the top of the footing, slab or damp-proof course where the first course starts, not from the finished ground.
5. Fixing sills and lintels after the wall starts. Check every fixed height against the story pole before laying the first course.
6. Assuming every brick is the same height. Bricks vary from batch to batch. Measure 10 bricks and use the average height for the calculation.