Mortar Calculator
Estimate mortar volume, bag quantities and optional cost for brick and concrete block walls.
Use this mortar calculator to prepare a planning estimate for brick or concrete block construction. Choose Imperial or Metric units, enter the wall size, select the masonry unit, joint thickness, waste and native mortar bag size, then review mixed mortar volume, whole bags and optional material cost.
Your Estimate
Net Wall Area
160.00 sq ft
Estimated Mortar Volume
20.85 cu ft
Bags Required Before Waste
32 bags
Waste-Adjusted Volume (10%)
22.93 cu ft
Waste-Adjusted Bags
35 bags
Uses an approximate mixed yield of 0.67 cu ft per 80 lb bag. Confirm the yield printed on the selected mortar product.
Results Actions
The estimate uses typical mortar-volume rates per 1,000 masonry units and adjusts them for the selected joint thickness. Unit dimensions, joint profile, wall configuration and installer technique can change actual usage.
Typical Masonry Units and Mortar Planning Rates
These are rough planning rates at the stated baseline joint. Actual mortar requirements vary with unit dimensions, wall thickness, joint profile and depth, tooling, bond, waste and installation method.
How to Use the Mortar Calculator
- 1Choose Imperial or Metric units; switching modes loads native wall, masonry-unit, joint and bag defaults.
- 2Enter the wall length and height in feet or meters.
- 3Select the brick or concrete block used for the wall.
- 4Select a 3/8 in or 1/2 in Imperial joint, or a 10 mm or 12 mm Metric joint.
- 5Choose a 5%, 10% or 15% waste allowance.
- 6Choose the native mortar bag size and optionally enter the local price per bag.
- 7Review wall area, estimated mixed mortar volume, base bags, waste-adjusted volume, total whole bags and optional cost.
Mortar Quantity and Bag Formulas
- 1Net wall area = wall length × wall height. Openings are not entered in this calculator, so subtract their area from the wall dimensions or calculate wall sections separately when needed.
- 2Nominal unit face area = (unit length + mortar joint) × (unit height + mortar joint).
- 3Estimated masonry units = wall area ÷ nominal unit face area, using consistent units.
- 4Baseline mortar volume = estimated units ÷ 1,000 × typical mortar volume per 1,000 selected units.
- 5Joint adjustment factor = selected joint thickness ÷ baseline joint thickness of 3/8 in or 10 mm.
- 6Estimated mortar volume = baseline mortar volume × joint adjustment factor.
- 7Bags required before waste = estimated mortar volume ÷ selected bag yield, rounded up.
- 8Waste-adjusted mortar volume = estimated mortar volume × (1 + waste percentage).
- 9Waste-adjusted bags = waste-adjusted volume ÷ selected bag yield, rounded up.
- 10Estimated material cost = waste-adjusted bags × price per bag when a price is entered.
Example Calculation
Imperial example: a 20 ft × 8 ft wall has 160 sq ft of area. Modular brick with a 3/8 in joint covers a nominal 8 in × 2 5/8 in face, producing an estimated 1,097 bricks. At a planning rate of 19 cu ft per 1,000 bricks, the wall requires about 20.85 cu ft of mortar before waste. Using an approximate 0.67 cu ft yield per 80 lb bag requires 32 bags before waste and 35 bags after 10% waste. Metric example: a 6 m × 2.4 m wall has 14.4 m² of area. A 190 × 90 × 57 mm brick with a 10 mm joint produces about 1,075 units. At 0.50 m³ per 1,000 bricks, estimated mortar is about 0.537 m³ before waste and 0.591 m³ after 10% waste. At an approximate 0.0135 m³ per 30 kg bag, round up to 44 bags.
Accuracy & Assumptions
- Results are planning estimates and do not specify mortar type, strength or mix design.
- The wall is treated as a solid rectangular face with no opening deductions; calculate separate wall sections or subtract openings before using the estimate.
- Masonry-unit count is estimated from actual face dimensions plus the selected bed and head joint.
- Typical mortar-volume rates are approximate and are scaled in direct proportion to the selected joint thickness.
- Joint depth, joint profile, bond pattern, wall thickness, corners, leads, cleanup and installer technique can materially change mortar usage.
- Bag yields are approximate mixed yields and vary by manufacturer, mortar type, water content and mixing method; use the package yield when available.
- Waste is applied after the base mortar-volume estimate, and all bag quantities round up to whole bags.
- Optional cost covers mortar bags only and excludes sand or additives when sold separately, delivery, tax, labor, equipment and masonry units.
- Mortar type and masonry construction must follow product instructions, approved plans and applicable code.
Frequently Asked Questions
How do I calculate mortar for a brick wall?
Estimate the number of bricks from wall area and the nominal brick-plus-joint face, multiply by a typical mortar rate for that brick, add waste, then divide by the bag yield and round up.
How much mortar does a 60 lb bag make?
This calculator uses about 0.50 cu ft of mixed mortar as a planning yield for a 60 lb bag. Product formulas vary, so use the yield printed on the bag whenever available.
How much mortar does an 80 lb bag make?
The planning yield used here is about 0.67 cu ft per 80 lb bag. Confirm the actual yield because mortar type, manufacturer and mixing water affect output.
Does a wider mortar joint require more mortar?
Yes. A wider bed and head joint generally uses more mortar. The calculator scales its baseline rate for either 3/8 in versus 1/2 in joints or 10 mm versus 12 mm joints.
How much waste should I add?
Five percent may suit controlled work, 10% is a common planning allowance, and 15% may suit complex walls or uncertain conditions. Dropped material, board loss, joint tooling and cleanup all affect waste.
Can I use this calculator for concrete blocks?
Yes. Imperial mode includes an 8 in × 8 in × 16 in concrete block, and Metric mode includes a 390 × 190 × 190 mm block. Confirm the actual unit dimensions and bedding method.
Does the calculator subtract doors and windows?
No. The entered length and height define net wall area. Calculate separate wall sections around openings or subtract opening area before preparing the final order.
What mortar type should I use?
Mortar type depends on the masonry units, exposure, structural requirements and project specification. Follow approved plans, local code and the masonry-unit and mortar manufacturers’ instructions.
Can I estimate Metric mortar bags?
Yes. Metric mode uses native 20 kg, 25 kg, 30 kg and 40 kg options with approximate yields in cubic meters. Regional products vary, so verify the package yield.
Does the estimated cost include labor or masonry units?
No. Optional cost is the waste-adjusted bag count multiplied by price per bag. Brick, block, grout, reinforcement, accessories, delivery, tax, labor and equipment are separate.
This calculator provides a preliminary mortar quantity and bag-cost estimate only. Actual usage varies with masonry-unit dimensions, wall thickness, bond, bed and head joint width and depth, joint profile, openings, corners, leads, tooling, waste, weather and installer technique. Confirm product compatibility, mortar type, mix requirements and bag yield with the masonry-unit supplier, mortar manufacturer, project specifications and mason. Structural and permitted masonry must follow approved plans and applicable code.