How many bricks do I need per square foot?

For US modular brick with 3/8 in joints it is 6.86 bricks per sq ft of single-wythe wall, or about 686 per 100 sq ft. The formula is 1 ÷ ((L + j) × (H + j)) with the brick face length L, face height H and joint j in feet; in inches it is 144 ÷ ((7 5/8 + 3/8) × (2 1/4 + 3/8)) = 144 ÷ 21. Multiply by the net wall area, add 5 to 10% for cuts and breakage, and round up. The table above lists other bricks and joints.

How do I calculate bricks for a wall with doors and windows?

Multiply the wall length by its height, take off the area of each door and window (the calculator has an opening button for them), and count bricks for what is left. For example, a 30 × 6 ft wall of 215 × 65 mm bricks with 10 mm joints, less a 3 × 7 ft door, is 159 sq ft and 920 bricks with 5% extra. Bricks cut around openings and at the ends are what the extra is for.

How much mortar do I need for 1,000 bricks?

Quikrete's data sheet for Mason Mix (No. 1136) says an 80 lb bag lays up to 37 standard bricks, so 1,000 US modular bricks with 3/8 in joints take at least 28 bags, and about 30 bags with the 10% the calculator adds because "up to" is a best case. Larger joints and bricks that are deeper or shorter take more mortar per brick, and the calculator scales the rate by the mortar in the joints around one brick. The joints themselves hold about 8.1 cu ft per 1,000 bricks, which is shown for information only.

Is it true that about 7 bags of masonry cement lay 1,000 bricks?

That is the common rule of thumb for modular brick (the BIA Technical Notes on Brick Construction give it), and the calculator shows it as a labelled cross-check: 10 bags for the example wall. It counts bags of masonry cement alone; the mortar is mixed with sand, about three parts sand to one of cement by volume, so the cement is only part of what you buy. The premixed bag count here has the sand in the bag, which is why it is a larger number and why the two are not comparable bag for bag. Use the rule to see whether the answer is in the right range, and the geometric count to buy by. Both are estimates.

Which mortar type do I need, N or S?

Type N is the general-purpose mortar for above-grade, non-load-bearing or lightly loaded walls and for most veneer and garden walls. Type S is stronger and is used below grade, for retaining or freestanding walls exposed to weather, and where the plans ask for it (ASTM C270 lists the types). The bag counts here are the same for either; the yield printed on your bag is what to check. Ask your supplier or the plans which type your wall needs.

What is a wythe, and how does a double wythe change the count?

A wythe is one vertical layer of masonry, one brick thick. A single-wythe wall is one brick deep; a double wythe is two layers side by side with a collar joint between them. The calculator doubles the bricks and adds the collar joint to the mortar: for example a 12 × 4 ft wall of Norman bricks as a double wythe takes 483 bricks with 10% extra.

How big is a brick, and why do the sizes differ?

US modular brick is 7 5/8 × 2 1/4 × 3 5/8 in; with a 3/8 in joint it is laid on an 8 × 2 5/8 in module (that is where 21 sq in per brick, and 6.86 per sq ft, come from). The UK and metric Europe use 215 × 65 × 102.5 mm bricks with 10 mm joints, a 225 × 75 mm module. Other makers and regions use other sizes, and old or hand-made bricks vary within a batch, so measure the brick you are buying and pick custom if it is not in the list. Queen and king brick are not listed because their sizes differ by maker.

How much extra should I order?

About 5% for a plain wall, 10% when there are many cuts, openings, corners or soft or hand-made brick. Order all the bricks for one wall together if you can: color and size vary between batches, and a later batch may not match. Mortar bags are rounded up once for the whole job, from the bricks you buy.

Brick Calculator: How Many Bricks and How Much Mortar Do I Need?

A wall 24 ft long and 8 ft high (192 sq ft) in US modular brick (7 5/8 × 2 1/4 × 3 5/8 in) with 3/8 in joints needs 1,383 bricks with 5% extra, laid in running bond. That is 6.86 per sq ft of wall, from 1 ÷ ((length + joint) × (height + joint)) with the sizes in feet. Mortar: 42 bags of 80 lb premixed Type N or S mortar, from Quikrete’s published laying rate of up to 37 bricks per 80 lb bag, with 10% added (the joints themselves hold about 10.6 cu ft). A double wythe (two bricks thick) doubles the bricks.

Figures based on the sources listed belowUpdated 2026-10-04How we calculate

Wall length

Wall height

Extra bricks

Typical: cuts and breakage (5%)Many cuts, openings or soft brick (10%)Exact (0%)Custom

Brick sizeFace length × face height × depth of the brick as laid, without the joint. Sizes vary by maker and region: check the brick you are buying, or pick custom.

Mortar joint thickness

3/8 in (0.375) is the US default; 10 mm (0.394 in) is the metric one. Pick mm in the unit box to type it in millimeters.

Wall thicknessA wythe is one vertical layer of bricks. A double wythe takes twice the bricks plus the mortar between the layers. Running bond is assumed; patterns with headers take more.

Mortar allowanceAdded on top of the manufacturer’s laying rate, which is a best case (“up to 37 bricks per 80 lb bag”). An estimate: droppings, furrowed beds and waste vary with the mason and the weather.

Price per brick (optional)

Buy 1,383 bricks

192 sq ft + 5% waste = 201.60 sq ft

Bricks per 100 sq ft of wall (before extra): 686 bricks
Mortar mix (premixed Type N or S, 80 lb bags): 42 bags (joints ≈ 10.6 cu ft)
Cross-check: masonry cement alone (rule of thumb, estimate): 10 bags, about 7 per 1,000 modular bricks, sand extra

Low

$691.50

Expected

$1,244.70

High

$2,212.80

Includes 9.60 sq ft waste

How this number is calculated

192 sq ft + 5% waste = 201.60 sq ft ÷ 0.146 sq ft per brick = 1,383 bricks

Shopping list

Brick trowel
Mason’s line and line blocks
Jointing tool (concave)
Mortar mixing tub
Brick hammer and chisel set
4 ft level
Wall ties (brick ties)

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Bricks per 100 sq ft by brick size and joint

Single-wythe wall in running bond, no extra, worked by this calculator at build time: 14,400 ÷ ((length + joint) × (height + joint)), with the brick face as laid. Add 5% for cuts and breakage, and double the count for a double wythe.
Brick	1/4 in joint	3/8 in joint	1/2 in joint	10 mm joint
US modular, 7 5/8 × 2 1/4 in face	732	686	645	680
US engineer modular, 7 5/8 × 2 3/4 in	610	576	546	572
US Norman, 11 5/8 × 2 1/4 in	486	458	432	454
US standard, 8 × 2 1/4 in	699	656	617	649
UK / EU metric, 215 × 65 mm	589	556	526	551

Mortar per 100 sq ft of US modular brick by joint

Single wythe, 7 5/8 × 2 1/4 × 3 5/8 in brick, 100 sq ft, no extra bricks, worked by this calculator at build time. Bags follow Quikrete's published laying rate (up to 37 standard bricks per 80 lb bag), scaled for the joint, with a 10% allowance (an estimate). The joint volume is bed plus head joint, shown for information; it does not set the bags. The last column is the rule of thumb, 7 bags of masonry cement per 1,000 bricks: cement only, so not comparable bag for bag (estimate).
Joint	Bricks	Joint volume (cu ft)	Bricks per bag (scaled)	Premixed bags (80 lb)	Cement-only rule (bags)
1/4 in	732	3.9	56.2	15	6
3/8 in	686	5.5	37	21	5
1/2 in	645	7	27.4	26	5
10 mm	680	5.8	35.2	22	5

Methodology & assumptions

Bricks per sq ft = 144 ÷ ((L + j) × (H + j)), with the brick face length L, face height H and joint j in inches: each brick takes up its own face plus one head joint along the course and one bed joint above it. Net wall area is the length × height less the doors and windows; bricks = net area × bricks per sq ft × (1 + extra), rounded up once, and a double wythe (a wall two bricks thick) has twice as many. Running bond is assumed, with no headers and no brick cut for corners or openings beyond the extra; header courses, soldier and other patterns use more bricks. Mortar bags follow the manufacturer's laying rate, scaled for your brick and joint. The Quikrete Mason Mix data sheet (No. 1136) says an 80 lb bag lays up to 37 standard bricks; this calculator reads that as US modular brick with 3/8 in joints, single wythe. For anything else the rate is scaled by the mortar in the joints around one brick, depth × (L × j + H × j + j²) (a bed joint plus a head joint, filled the full depth of the brick), plus the collar joint between the wythes of a double wythe, relative to a modular brick at 3/8 in: bags = bricks ÷ 37 × that factor × (1 + allowance), rounded up once. Because "up to" is a best case, an allowance is added on top: 10% by default, or none, or 25% (estimates; droppings, furrowed bed joints and mortar left in the tub vary with the mason and the weather). Bricks are counted with your extra, since the bricks you buy include the ones you cut. The geometric volume of the joints is shown for information, but it does not set the bag count: it ignores furrowing, droppings and the real yield of a bagged mix. Other brands and Type N or S mixes lay a different number per bag, so check your bag. The cross-check line is the common rule of thumb of about 7 bags of masonry cement per 1,000 modular bricks, applied to the bricks laid without the extra. It counts cement only, which is mixed with about three times its volume of sand, so it is not the same as a count of premixed bags: it is there to show that the two methods land in the same order of magnitude, not to replace one with the other (estimate). Brick sizes vary by maker and region: use the size printed on your brick or pick custom, and use the joint your mason or plans call for. The metric toggle shows lengths in m, and the brick and joint sizes can be typed in mm.

Brick Industry Association (BIA), Technical Notes on Brick Construction: Dimensioning and Estimating Brick Masonry (modular sizes, bricks per square foot by joint, mortar quantities)
Quikrete, DATA SHEET Mason Mix 1136: an 80 lb bag lays up to 37 standard bricks (or 13 8 × 8 × 16 blocks)
ASTM C270, Standard Specification for Mortar for Unit Masonry (Types N, S, M and O)
BS EN 771-1, Specification for masonry units: clay masonry units, and BS 3921 (work size of the common metric brick: 215 × 102.5 × 65 mm, with 10 mm joints)
About 7 bags of masonry cement per 1,000 modular bricks: BIA Technical Notes on Brick Construction, Dimensioning and Estimating Brick Masonry (rule of thumb, estimate)
The 10% mortar allowance and the typical brick price range: rules of thumb (estimates), not from a single document

How to calculate bricks and mortar for a wall

Measure the wall. Measure the length and height of each wall in feet (decimals), and the doors and windows to take off.
Pick the brick and joint. Use the size printed on the brick and the joint your plans or mason call for: 3/8 in for US brick, 10 mm for metric.
Count the bricks. Bricks per sq ft = 1 ÷ ((length + joint) × (height + joint)) in feet. Multiply by the net wall area, double it for a double wythe, and add 5 to 10% for cuts and breakage.
Work out the mortar. An 80 lb bag of premixed mortar lays up to 37 standard bricks (Quikrete Mason Mix data sheet). Divide the bricks by 37, scale for a larger joint or brick, and add about 10% because 37 is a best case.
Round up. Round the bags up once for the whole job, and check the rate printed on the bag you buy.

Worked examples

Project	Result
24 ft long, 8 ft high wall, US modular brick, 3/8 in joints, single wythe	192 sq ft + 5% extra → 1,383 bricks, 42 bags of mortar
30 ft long, 6 ft high wall with a 3 × 7 ft door, 215 × 65 mm brick, 10 mm joints	159 sq ft + 5% extra → 920 bricks, 36 bags of mortar
12 ft long, 4 ft high garden wall, US Norman brick, double wythe, 3/8 in joints	48 sq ft + 10% extra → 483 bricks, 27 bags of mortar
40 ft long, 10 ft high wall, US modular brick, 1/2 in joints, no extra	400 sq ft + 0% extra → 2,578 bricks, 104 bags of mortar

Frequently asked questions

How many bricks do I need per square foot?: For US modular brick with 3/8 in joints it is 6.86 bricks per sq ft of single-wythe wall, or about 686 per 100 sq ft. The formula is 1 ÷ ((L + j) × (H + j)) with the brick face length L, face height H and joint j in feet; in inches it is 144 ÷ ((7 5/8 + 3/8) × (2 1/4 + 3/8)) = 144 ÷ 21. Multiply by the net wall area, add 5 to 10% for cuts and breakage, and round up. The table above lists other bricks and joints.
How do I calculate bricks for a wall with doors and windows?: Multiply the wall length by its height, take off the area of each door and window (the calculator has an opening button for them), and count bricks for what is left. For example, a 30 × 6 ft wall of 215 × 65 mm bricks with 10 mm joints, less a 3 × 7 ft door, is 159 sq ft and 920 bricks with 5% extra. Bricks cut around openings and at the ends are what the extra is for.
How much mortar do I need for 1,000 bricks?: Quikrete's data sheet for Mason Mix (No. 1136) says an 80 lb bag lays up to 37 standard bricks, so 1,000 US modular bricks with 3/8 in joints take at least 28 bags, and about 30 bags with the 10% the calculator adds because "up to" is a best case. Larger joints and bricks that are deeper or shorter take more mortar per brick, and the calculator scales the rate by the mortar in the joints around one brick. The joints themselves hold about 8.1 cu ft per 1,000 bricks, which is shown for information only.
Is it true that about 7 bags of masonry cement lay 1,000 bricks?: That is the common rule of thumb for modular brick (the BIA Technical Notes on Brick Construction give it), and the calculator shows it as a labelled cross-check: 10 bags for the example wall. It counts bags of masonry cement alone; the mortar is mixed with sand, about three parts sand to one of cement by volume, so the cement is only part of what you buy. The premixed bag count here has the sand in the bag, which is why it is a larger number and why the two are not comparable bag for bag. Use the rule to see whether the answer is in the right range, and the geometric count to buy by. Both are estimates.
Which mortar type do I need, N or S?: Type N is the general-purpose mortar for above-grade, non-load-bearing or lightly loaded walls and for most veneer and garden walls. Type S is stronger and is used below grade, for retaining or freestanding walls exposed to weather, and where the plans ask for it (ASTM C270 lists the types). The bag counts here are the same for either; the yield printed on your bag is what to check. Ask your supplier or the plans which type your wall needs.
What is a wythe, and how does a double wythe change the count?: A wythe is one vertical layer of masonry, one brick thick. A single-wythe wall is one brick deep; a double wythe is two layers side by side with a collar joint between them. The calculator doubles the bricks and adds the collar joint to the mortar: for example a 12 × 4 ft wall of Norman bricks as a double wythe takes 483 bricks with 10% extra.
How big is a brick, and why do the sizes differ?: US modular brick is 7 5/8 × 2 1/4 × 3 5/8 in; with a 3/8 in joint it is laid on an 8 × 2 5/8 in module (that is where 21 sq in per brick, and 6.86 per sq ft, come from). The UK and metric Europe use 215 × 65 × 102.5 mm bricks with 10 mm joints, a 225 × 75 mm module. Other makers and regions use other sizes, and old or hand-made bricks vary within a batch, so measure the brick you are buying and pick custom if it is not in the list. Queen and king brick are not listed because their sizes differ by maker.
How much extra should I order?: About 5% for a plain wall, 10% when there are many cuts, openings, corners or soft or hand-made brick. Order all the bricks for one wall together if you can: color and size vary between batches, and a later batch may not match. Mortar bags are rounded up once for the whole job, from the bricks you buy.

Handy tools

Feet and Inches Calculator: Turn a tape reading in feet, inches and fractions into the decimal feet the wall length and height fields take.