Calculated result
17bags
Mortar bags to order
Formula
MAS-MRT-001mortar ft³ = area ÷ 100 × 5.5; bags = ceil(mortar × (1 + waste) ÷ bag yield)
8.8 ft³
Net mortar volume
9.68 ft³
Volume including waste
0.6 ft³ / bag
Stated bag yield
Masonry calculator
Mortar calculator
Default example (160 ft² net wall area, 10% waste factor): Mortar bags to order is 17 bags. In metric, net mortar volume is 0.25 m³.
Formula. mortar ft³ = area ÷ 100 × 5.5; bags = ceil(mortar × (1 + waste) ÷ bag yield)
Type N/S mortar volume and bag count from net wall area using a published 5.5 ft³ per 100 ft² rule of thumb.
By Feroz Sheikh · Formula MAS-MRT-001 v1.0.0 · Tested formula
Formula
MAS-MRT-001v1.0.0Project inputs
Enter your measurements. Switching units converts the same project, including coverage and unit rates. Package yields keep the unit printed beside each field.
Refine measurements and rates at any time. Your current values are included in the material-list PDF.
Planning estimate, not engineering advice. Confirm site measurements and product specifications. Calculation limits.
This calculator converts net masonry face area into mortar volume using 5.5 ft³ per 100 ft², then rounds to whole bags.
- Measure net face area after openings.
- Pick the bag size you will actually buy.
- Confirm joint thickness with the mason — it moves yield more than the bag label.
Add your project costs
Enter supplier prices and any labour, equipment or delivery costs. Pick a currency — badges, inputs, and totals follow.
Costs use the block, brick or mortar rate you type. Construclytic does not fetch masonry prices. Lintels, corners and labour stay separate estimate lines.
How this calculator works
A transparent mortar bags takeoff.
Feroz SheikhWritten and reviewed by Feroz Sheikh · founder
This calculator converts net masonry face area into mortar volume using 5.5 ft³ per 100 ft², then rounds to whole bags.
MAS-MRT-001 uses a published yield — commonly 5.5 ft³ of mortar per 100 ft² of wall with the selected unit — then bags from the labelled yield. Type N and Type S do not share a bag. Grout fill is a different calculator.
Block-wall litres are derived on the GCC guide
Face-shell and solid-bed litres for 100, 150 and 200 mm units, then 50 kg bags for mixes 1:4, 1:5 and 1:6, are in mortar for a block wall per square metre. This calculator still uses 5.5 ft³ per 100 ft². The two rules are not the same number.
Worked example. Example: 160 ft² of wall at 10% waste is 9.68 ft³ of mortar, which rounds to 17 of the 80 lb bags at a 0.60 ft³ yield.
See the example inputs and calculated result
This separate example uses the calculator's starting values in imperial units. It stays unchanged when you edit the tool above. Example rates, yields and dimensions are assumptions, not recommendations for your project.
| Input | Example value |
|---|---|
| Net wall area | 160 ft² |
| Bag size | 80 lb |
| Waste factor | 10 % |
Example result: Mortar bags to order — 17 bags.
mortar ft³ = area ÷ 100 × 5.5; bags = ceil(mortar × (1 + waste) ÷ bag yield)
Use the labelled units above when reproducing this example. To work in metric, switch the calculator to Metric; applicable measurements are converted, while product-specific units remain labelled.
- 1. Measure net face area after openings.
- 2. Pick the bag size you will actually buy.
- 3. Confirm joint thickness with the mason — it moves yield more than the bag label.
Field notes that change the number
- Net wall area after openings is the usual start.
- Enter the bag yield on the sack you will buy.
- Pigment, lime and waterproofing admix are extras.
Common mistakes
- Using grout-fill volume as laying mortar.
- Ignoring the unit type on the yield table.
- Treating this as a structural grout design.
Need the broader workflow? Read the masonry planning guide.
How-to: How to count CMU and brick
Questions
Questions about mortar bags
Is this a mix design?
No. Type N versus S, sand grading and water are a mason and specification decision.
Why 5.5 ft³ per 100 ft²?
It is a common 3/8 in joint rule of thumb for modular brick and 8 in CMU bed joints. Change the result if the joint is thicker.
What is the formula ID?
This mortar calculator publishes formula MAS-MRT-001, version 1.0.0. The ID stays on the result and on the estimate line.