Calculate how many concrete blocks and bags of mortar are needed for your project by entering your wall dimensions and block size. Add the block price to get an estimated material price estimate.

## Material Estimate:

**Blocks **

Bags of Mortar

yds^{3} Sand

### Estimated Material Cost:

Block Cost

Mortar Cost

Sand Cost

Total Cost

Learn how we calculated this below

scroll down

## On this page:

- Concrete Block Calculator
- How Many Concrete Blocks Do I Need?
- How to Calculate Concrete Blocks
- How to Estimate Mortar for a Block Wall
- How to Estimate Grout or Concrete Fill
- Tools Needed to Install a Concrete Block Wall
- Standard Concrete Block Sizes
- How Much Does a Block Wall Cost?
- References

[ see all ]

By

Joe Sexton

Joe is the creator of Inch Calculator and has over 20 years of experience in engineering and construction. He holds several degrees and certifications.

Full bio

## How Many Concrete Blocks Do I Need?

Concrete blocks are an affordable building material that can be used for many construction projects and are suited very well for construction walls for foundations or utility buildings.

Concrete blocks typically have holes in the center to reduce the weight, the material needed, and the cost. The average concrete block is composed of cement and coal ash, which is why they are often called cinder blocks.

Concrete blocks are concrete masonry units, or CMUs,^{[1]} but we often refer to them as concrete blocks or cinder blocks.

You might be here because you’re wondering how many concrete blocks you’ll need for your project.

A concrete block wall typically requires **1 ^{1}/_{8} blocks per square foot**.

Keep reading to learn the process to calculate the number of concrete blocks you need, or just use the calculator above. Simply enter the dimensions of your wall project, and the concrete block calculator will figure out how many blocks you need.

**Note:** Retaining walls are a bit different from a typical concrete block wall. If you’re building a retaining wall, then try our retaining wall calculator.

## How to Calculate Concrete Blocks

There are several formulas to figure out how many concrete blocks are necessary for a wall project, but you’ll need to start by measuring the wall’s width and height in feet.

### Step One: Find Wall Square Footage

Once you have the wall measurements, calculate the square footage by multiplying the width times the height.

wall sq ft = width × height

### Step Two: Find Block Square Footage

Now you need to figure out the square footage of the block you are using. The standard block size is 16″ wide x 8″ high. Multiply 16×8, and then divide by 144 to get the answer.

block sq ft = 16 × 8 / 144 = 0.89 sq. ft.

Different size blocks will have different square footages; apply the formula above to find the solution. Check out our square footage calculator to determine the square footage of your block.

### Step Three: Calculate Blocks

After you have found the square footage of both your wall and your block, determining the number of blocks you need is as simple as dividing the wall square footage by the block square footage.

blocks = wall sq ft / block sq ft

If you’re using a standard 16″ x 8″ x 8″ block, find the number of blocks needed by dividing the wall square footage by 0.89.

blocks = wall sq ft / 0.89

We recommend adding 5%-10% additional blocks to account for broken blocks or blocks that need to be cut for the edges.

Our calculator above may indicate a different quantity of blocks needed since it uses a more precise formula, accounting for partial blocks and cutoffs automatically.

## How to Estimate Mortar for a Block Wall

Calculating the amount of mortar needed for the joints in a concrete block wall will vary depending on the mortar mix you use. On average, it takes about three bags of cement for every 100 blocks.

Divide the number of blocks being installed by 33.3 to calculate how many bags are needed. Standard mortar requires a 1:3 cement to sand mix, which amounts to 1 yd^{3} of sand for every seven bags of cement.

You can also purchase pre-mixed bags of mortar, which generally yield around 12 blocks per 80-pound bag. Try our mortar calculator to calculate how many bags are needed.

## How to Estimate Grout or Concrete Fill

Estimating the concrete needed to fill the voids in concrete block involves finding the volume of the void in the block being used and multiplying that by the number of voids in the wall. Measure the length, width, and height of the void in inches, then multiply to get the void’s cubic inches.

Multiply the cubic inches by the number of voids in the wall, typically 2 per block. Finally, divide cubic inches by 46,656 to find cubic yards of concrete needed.

Use our block fill calculator to estimate the fill volume.

If you’re installing a concrete block wall, you will need several tools to correctly do the job. Here is a small list of tools that are necessary to build a wall.

- Brick Trowel: This is used to lay an even bed of mortar when setting block.
- Mason Line: Use mason line to ensure the wall is straight and level and the block is set at an even height.
- Level: Make sure you have a level on hand to verify that each block is straight and level with adjacent blocks.
- Jointer: A jointer will help get smooth, clean joints for a professional look.
- Tape Measure: You’re definitely going to need a tape measure for this one.
- Mixing Tub: Mix mortar in a mixing tub to keep your wheelbarrow clean.

As an Amazon Associate we may earn commissions from qualifying purchases from Amazon. Learn more

## Standard Concrete Block Sizes

You’ll need to know the size of the concrete block you’ll be using to determine how many blocks you need for your project. The most common sizes are 8″ high by 8″ wide and 8″ high by 16″ wide in varying thicknesses.

The block’s thickness is not critical to finding how many blocks you need, but it is essential when estimating how much mortar and other masonry material you need. The common thicknesses are 4″, 6″, 8″, 10″, 12″, and 14″.

Refer to the tables below for standard block sizes, including the nominal dimensions. The nominal size is the block’s actual size, while the size includes a 3/8″ mortar joint and is the size that should be used when estimating material.

The standard mortar joint should be 3/8″ thick for your wall.

### 2″ and 3″ CMU Block Dimensions

Size D x H x W | Nominal D x H x W | Blocks per 100 ft^{2} |
---|---|---|

2″ x 8″ x 16″ | 1 ^{5}⁄_{8}” x 7 ^{5}⁄_{8}” x 15 ^{5}⁄_{8}“ | 113 |

3″ x 8″ x 16″ | 2 ^{5}⁄_{8}” x 7 ^{5}⁄_{8}” x 15 ^{5}⁄_{8}“ | 113 |

### 4″ CMU Block Dimensions

Size D x H x W | Nominal D x H x W | Blocks per 100 ft^{2} |
---|---|---|

4″ x 8″ x 8″ | 3 ^{5}⁄_{8}” x 7 ^{5}⁄_{8}” x 7 ^{5}⁄_{8}“ | 226 |

4″ x 8″ x 16″ | 3 ^{5}⁄_{8}” x 7 ^{5}⁄_{8}” x 15 ^{5}⁄_{8}“ | 113 |

### 6″ CMU Block Dimensions

Size D x H x W | Nominal D x H x W | Blocks per 100 ft^{2} |
---|---|---|

6″ x 8″ x 8″ | 5 ^{5}⁄_{8}” x 7 ^{5}⁄_{8}” x 7 ^{5}⁄_{8}“ | 226 |

6″ x 8″ x 16″ | 5 ^{5}⁄_{8}” x 7 ^{5}⁄_{8}” x 15 ^{5}⁄_{8}“ | 113 |

### 8″ CMU Block Dimensions

Size D x H x W | Nominal D x H x W | Blocks per 100 ft^{2} |
---|---|---|

8″ x 8″ x 8″ | 7 ^{5}⁄_{8}” x 7 ^{5}⁄_{8}” x 7 ^{5}⁄_{8}“ | 226 |

8″ x 8″ x 16″ | 7 ^{5}⁄_{8}” x 7 ^{5}⁄_{8}” x 15 ^{5}⁄_{8}“ | 113 |

### 10″ CMU Block Dimensions

Size D x H x W | Nominal D x H x W | Blocks per 100 ft^{2} |
---|---|---|

10″ x 8″ x 8″ | 9 ^{5}⁄_{8}” x 7 ^{5}⁄_{8}” x 7 ^{5}⁄_{8}“ | 226 |

10″ x 8″ x 16″ | 9 ^{5}⁄_{8}” x 7 ^{5}⁄_{8}” x 15 ^{5}⁄_{8}“ | 113 |

### 12″ CMU Block Dimensions

Size D x H x W | Nominal D x H x W | Blocks per 100 ft^{2} |
---|---|---|

12″ x 8″ x 8″ | 11 ^{5}⁄_{8}” x 7 ^{5}⁄_{8}” x 7 ^{5}⁄_{8}“ | 226 |

12″ x 8″ x 16″ | 11 ^{5}⁄_{8}” x 7 ^{5}⁄_{8}” x 15 ^{5}⁄_{8}“ | 113 |

### 14″ CMU Block Dimensions

Size D x H x W | Nominal D x H x W | Blocks per 100 ft^{2} |
---|---|---|

14″ x 8″ x 8″ | 13 ^{5}⁄_{8}” x 7 ^{5}⁄_{8}” x 7 ^{5}⁄_{8}“ | 226 |

14″ x 8″ x 16″ | 13 ^{5}⁄_{8}” x 7 ^{5}⁄_{8}” x 15 ^{5}⁄_{8}“ | 113 |

## How Much Does a Block Wall Cost?

A wall typically costs $10 – $15 to install; learn more about a wall project’s cost factors. We suggest getting several professional estimates to get the best labor cost and find the right company for your project.

Check out our concrete calculator to help with your other concrete projects.

## FAQs

### How do I figure out how many concrete blocks I need? ›

**Calculate the area of a block by multiplying its height and width.** **Divide your wall area by the block area**. The result is the total amount of blocks you need.

**How much cement do I need for 100 blocks? ›**

Post your job to find high quality tradespeople and get free quotes. If you are using 100mm blocks you will require 1 ton of red building sand and **8 bags** of cement.

**How many blocks can fence 50 by 100? ›**

If you mean the fence is 50 blocks high and 100 blocks long then the answer is 50 X 100 or **5,000 blocks** total.

**How many blocks will a bag of concrete fill? ›**

Coverage - Each 80 lb (36.2 kg) bag of QUIKRETE Core-Fill Grout – Coarse will fill the cores of approximately **3 standard 8 in x 8 in x 16 in (200 mm x 200 mm x 405 mm) blocks**.

**How do you calculate block work quantity? ›**

- First determine the Width, Height, and Thickness of the Wall. ...
- Now the calculate the volume of the wall. ...
- The volume of the Openings. ...
- Subtract the volume of the Openings from Volume of Walls. ...
- Now calculate the volume of the concrete block with the Mortar allowance. ...
- Divide the total volume of a wall by volume of one block.

**How many blocks is a mile? ›**

North-south is easy: **about 20 blocks** to a mile. The annual Fifth Avenue Mile, for example, is a race from 80th to 60th Street. The distance between avenues is more complicated. In general, one long block between the avenues equals three short blocks, but the distance varies, with some avenues as far apart as 920 feet.

**How many block can you lay with an 80 lb bag of mortar? ›**

Each 80 lb (36.2 kg) bag of QUIKRETE® Mortar Mix will lay up to **37 standard bricks** or 13 standard (8 in by 8 in by 16 in [200 mm by 200 mm by 405 mm]) blocks.

**How many block should a mason lay in a day? ›**

When a mason is laying between **90 to 120 block per day**, every pound matters. ProBlock's light unit weight and its open end design allows the mason to go around rebar instead of up and over, thereby reducing the risk of back and shoulder injuries.

**How thick should mortar be for concrete blocks? ›**

The mortar joints used in concrete block and brick construction are usually **10 mm** thick. For AAC block construction, a special type of mortar is used (2-3 mm) and this is a pre-mixed cement-based product with higher quality than normal mortar.

**How many blocks will fence a 60 by 120 plot of land? ›**

This means that it will take **3,252 blocks** to fence a dry land with a size of 60 by 120 to a height of 12ft using 6 inches block. If you want to know the cost, the bill of quantity for any of your projects before the commencement of it. We are here to work with you.

### How many blocks can fence a 100 by 100 plot? ›

Thus, the number of blocks required to fence a plot of land measuring 100ft by 100ft is **3580 blocks** and this is the case where the fence it required to be 10 blocks high.

**How many blocks will build a 12 by 12 room? ›**

You will need to multiply the length of the wall by the height to get the area. Multiply that area by 60 to get the number of bricks you should need, then add 10% for wastage. For a 144 sq ft room (12×12 feet), you will need **1713 bricks** to make a brick wall.

**How many bags of cement can lay 500 blocks? ›**

Yes **4 bags** will be sufficient for 500 bricks, using a 10mm bedding course. Mix ratio 5 sand 1 cement. The general rule is 1kg of mortar (sand and cement) per brick, so 500kg of mortar on a 4:1 mix ratio would equate to 100kg of cement, so that's 4 bags.

**How many bags of cement can build 1000 blocks? ›**

To lay 1000 bricks = **3 bags cement** + 0.6 cu. m. sand. 1 Bag of cement to 3 wheelbarrows of building sand.

**How many 9 inches blocks can a bag of cement lay? ›**

By inference, we can say that we need 1 bag of cement to lay **50 pieces** of hollow 9 inches block (i.e 5 m^{2} of wall).

**What is a block formula? ›**

The Formula block **evaluates a user-defined equation and outputs the result of the evaluation as a True/False, numeric, or an instrument type output**. The block recalculates and outputs its value whenever any of the connectors referenced in its internal formula changes.

**How do you calculate construction quantity? ›**

To calculate the quantities of materials, you need to **multiply the total centre line length with breadth and depth of the construction**. The centre line length will be reduced by half of breadth of every junction where the main wall is joined with the cross walls, partitions or verandah.

**How far is 10 blocks to walk? ›**

10 blocks (**0.5 mile**) takes about 10 minutes to walk. Most people walk about 3 miles per hour or 1 block per minute.

**Is 8 city blocks a mile? ›**

Oblong blocks range considerably in width and length. The standard block in Manhattan is about 264 by 900 feet (80 m × 274 m). In Chicago, a typical city block is 330 by 660 feet (100 m × 200 m), meaning that **16 east-west blocks or 8 north-south blocks measure one mile**, which has been adopted by other US cities.

**Is 7 blocks a mile? ›**

Generally speaking, the distance between avenues is roughly 750 feet, which means **about seven east-west blocks per mile**. But there's some serious variance.

### How much does 50 lbs of mortar cover? ›

FLOOR APPLICATION | WALL APPLICATION | COVERAGE (based on 50lbs bag) |
---|---|---|

4 inch - 12 inch Tile | 4 inch - 12 inch Tile | 75 - 85 Sq Ft |

12 inch - 16 inch Tile | 12 inch - 16 inch Tile | 60 - 70 Sq Ft |

16 inch or larger | 16 inch or larger | 40 - 50 Sq Ft |

Tile thicker than 3/8 inch | Tile thicker than 3/8 inch | 40 - 50 Sq Ft |

**How many cement blocks can be laid in a day? ›**

Each brickie should be building **250-300 blocks** in a day esp with no insulation to worry about.

**How many cubic feet is an 80 pound bag? ›**

80 lb. bag contains 0.023 cubic yards, or **0.63 cubic feet**. 3,000 lb. bag contains 0.88 cubic yards or 23.75 cubic feet of dry material.

**How long does it take to lay 200 blocks? ›**

You are looking at 200 blocks on a good day. That would be a **3 day** job as you'd have to dig a footings trench at least a foot to a foot and a half deep equally allow concrete to set, securing the weight of the concrete blocks.

**How many blocks can be laid in an hour? ›**

How many blocks can be laid in an hour? The fastest bricklayers can mortar and place **over 700 bricks** an hour.

**How many blocks can a bricklayer set in a day? ›**

Under normal circumstances, it is expected that the mason will lay **a minimum of 100 blocks per day**. Daily pay type of contract is suitable for small jobs or jobs where extreme carefulness is required such as block wall setting out and forming.

**Should you wet concrete blocks before laying? ›**

Concrete block **must never be wetted before or during laying a wall** [2].

**Should mortar be harder than blocks? ›**

**Mortar should never be stronger than the bricks**" is a well-known maxim in the bricklaying world. In this context, "stronger" does not mean its load-bearing capacity, but the mortar's hardness and permeability. Hard, dense mortar should not be used to surround porous, open-textured bricks.

**How many bags of mortar do I need for 100 block? ›**

**Three bags** of mortar are estimated for every 100 block, therefore 6-3/4 bags of mortar are needed ((225 block x 3 bags mortar) / 100 block = 6-3/4 bags of mortar). One cubic yard of sand is required for every 7 bags of mortar, therefore, the mason must also purchase .

**Is 60 by 120 a plot of land? ›**

**In Lagos state, the standard size of a plot is 60 x 120 ft** (18m x 36m, i.e., 648sqm), while in some other cities in the country, the land is measured at 50 x 100 ft. Acres and hectares are bigger measurement units mainly used for larger land areas like farmland and forests.

### How much fencing do I need to cover 1/2 acre? ›

What is the minimum fence footage for half an acre? On average, the minimum number of feet needed to enclose half an acre with fencing is around **590 feet**. Most half acres will require more footage to make up for odd shapes and various perimeters.

**How many linear feet of fence do I need for 10 acres? ›**

4) 660 (linear feet) x 4 (sides) = **2,640 linear feet** to enclose 10 Acres.

**How big is a 100 by 100 plot of land? ›**

**A hectare** is one of the lease known metric units and one which potential buyers and Estate developer seems tostruggle with - it is a land measuring100m x 100m OR 328ft x 328ft OR 10,000sqm. It is about two and half acres. A Hectare consist of 15 plots.

**What is a maximum length of a block? ›**

Today, let's talk about block length. Subdivision regulations are notorious for allowing maximum block lengths that are **1,200–1,600 feet**. If you look at most well-established neighborhoods dating back to the first few decades of the 20th century, you're more likely to see blocks ranging from 300-650 feet long.

**How many houses can fit in a 50 by 100 plot? ›**

50 by 100 house plans in Kenya can hold up to **7 one-bedroom units of houses on one floor** and if the building is a mansion with 4 floors it brings a total of 28 units of houses.

**How many blocks do I need for a 3 bedroom house? ›**

Ultimately, the total number of blocks required to complete the construction of a three-bedrooms flat = 903 + 1452 + 677 = **3032 blocks** (disregarding wastage).

**How many blocks will build a 10 by 10 room? ›**

In the construction of a single room in Nigeria, you will need an estimate of about **420 to 600 blocks**.

**How much cement do I need to lay 1000 blocks? ›**

You need **3,6 bags** of cement and 17.5 Cft of coarse sand to do the work with 1000 Bricks.

**How many bags of cement do I need for 3000 blocks? ›**

Approximately 8 bags of cement will be required for M20 per cu.

**How many 6 inches blocks can 1 bag of cement lay? ›**

In terms of making mortar for mason one bags of cement mortar (soft mixture of sharp sand and cement used in laying blocks) can lay up to **100 solid blocks** (6inch) or 100 hollow blocks (8inch). The bigger the size of the block the lesser the number.

### How many cement blocks do I need calculator? ›

**Calculate the area of a block by multiplying its height and width.** **Divide your wall area by the block area**. The result is the total amount of blocks you need.

**How do you calculate cement for block laying? ›**

**Divide the number of blocks in the wall by the number of blocks each bag of mortar can bond if using solid blocks**. This value is given by the manufacturer and is stated on the bag. The result is the number of bags of mortar needed.

**How much concrete do I need per block? ›**

Concrete cell fill calculator: sample calculation

The core volume of a standard size 6-inch concrete block is approximately 392 in³ or 0.006424 m³. From our calculations above, we can now say that we need around **0.5782 m³** of concrete or mortar to fill the concrete blocks that we will use to construct our wall.

**How many 5 inches blocks can a bag of cement produce? ›**

1 bag of cement can lay approximately **70 to 80** cement blocks.

**How many bags of cement do I need to set 100 blocks? ›**

How are bags of cement required to set 100 blocks? You need to input the dimensions of the concrete blocks and number and this will compute the cement required. the number of bags of cement (40 kgs.) needed to lay 100 blocks is **between 4 to 6** depending on the size of your blocks.

**How many 8 inch concrete blocks are on a pallet? ›**

Standard Green Hollow Block (**96/Pallet**) 8613.0001 - The Home Depot.

**What is the formula for making concrete blocks? ›**

Concrete blocks are often made of **1:3:6 concrete with a maximum size aggregate of 10mm or a cement-sand mixture with a ratio of 1:7, 1:8 or 1:9**. These mixtures, if properly cured, give concrete blocks a compression strength well above what is required in a one-storey building.

**How many concrete blocks should you lay in a day? ›**

there are a lot factors involved, Size and weight of blocks, amount of corners and returns to build, expect anything between **100 to 150 tops**.

**How many hollow blocks required for 100 sq ft? ›**

Divide The Total Volume Of The Wall By Volume Of One Block:

So the total numbers of blocks required = 86 + (86 x 5/100) = 86 + 4 = **90**.

**How far apart should concrete blocks be? ›**

Lay out the block, making sure to leave a **3/8 inch** gap between the blocks to allow for the vertical mortar joints (i.e., a typical 8x8x16 block is actually 15-5/8 inches long and 7-5/8 inches high to accommodate the mortar joint).

### What is the ratio of mortar mix for concrete blocks? ›

The standard ratio for average mortar mix is 3:1 or 4:1 for bricklaying. If you are using a pointing mix, then you should have a ratio of 1:4 or 1:5 mortar to sand. As for concrete, it depends on the strength you need it to be at. Usually, it is good practice to mix concrete at 1:2 mix to materials.

**Is it cheaper to make your own concrete blocks? ›**

So, in the end, yes, making your own pavers usually costs half the price of buying from the store. **Making your own pavers is objectively cheaper**, from a mathematical point of view.

**How much cement is needed to make 1000 blocks? ›**

To lay 1000 bricks = **3 bags cement + 0.6 cu.** **m.** **sand**. 1 Bag of cement to 3 wheelbarrows of building sand.

**How many cinder blocks can you lay in a day? ›**

When a mason is laying between **90 to 120 block per day**, every pound matters. ProBlock's light unit weight and its open end design allows the mason to go around rebar instead of up and over, thereby reducing the risk of back and shoulder injuries.

**How many blocks can a mason lay in an hour? ›**

How many blocks can be laid in an hour? The fastest bricklayers can mortar and place **over 700 bricks** an hour.

**How many concrete blocks per square foot? ›**

To calculate how many block you need, figure how many square feet of wall you have and **multiply by 1.125**.

**How many blocks is 1000 square feet? ›**

You will need approximately **25,000 to 34,000 bricks** for 1000 sq. feet.

**How many cement blocks required for 1,000 square feet? ›**

For 1000 sqft, we require a minimum of **25000 to 34000 bricks**.

**How deep should a footing be for a block wall? ›**

Normally a foundation wall with seven rows of blocks will be 24 inches wide and 12 inches deep and should have a footing 30 inches below grade. Remember to build a leveled footing where the cinder block will be placed.

**How deep should footings be for a 6 foot wall? ›**

All footings should be **a minimum of 150mm (6") in depth**, with the bottom 350 - 400mm (14-16") below ground level on most soils. For clay soil however, thicker and deeper footings should be used.

### How thick should mortar be between cinder blocks? ›

Also, remember that all the mortar joints—beneath the blocks and between the blocks—must be **3/8-inch** thick.