Brick Mortar Calculator | Free Construction Calculators

Calculate precise mortar quantities needed for brick masonry projects with our professional mortar calculator. Determine exact amounts of pre-mixed mortar bags, portland cement, hydrated lime, and masonry sand required for standard modular, queen, king, engineer, utility, and closure brick installations. Our calculator accounts for different mortar joint thicknesses from 3/8 inch thin joints to 5/8 inch thick joints, helping contractors, masons, builders, and DIY enthusiasts accurately estimate Type N, Type S, Type M, and Type O mortar requirements. Get instant calculations for cubic feet, cubic yards, 80-pound bag quantities, and component mix ratios to prevent costly material shortages or waste. Perfect for brick walls, chimneys, garden walls, retaining walls, and masonry restoration projects requiring accurate mortar estimation.

Accurate Mortar Quantities

Calculate bags, cubic feet, and component materials for precise ordering

Multiple Joint Sizes

Support for 3/8″, 1/2″, and 5/8″ mortar joint thicknesses

Mix Ratio Guidance

Detailed mixing ratios for Type N, S, M, and O mortar specifications

How to Use This Calculator

  1. Enter the total number of bricks for your project (calculate using our Brick Quantity Calculator)
  2. Select your brick size from standard modular, queen, king, engineer, utility, or closure
  3. Choose the mortar joint thickness - 1/2 inch is standard for most applications
  4. Click Calculate to see mortar needed in cubic feet, cubic yards, and 80-lb bags
  5. Review mix ratios if making custom mortar instead of using pre-mixed bags
  6. Order 10-15% extra mortar to account for mixing errors, spills, and waste

Calculation Formula

Mortar volume: Number of Bricks × Mortar per Brick (varies by size and joint thickness)

Standard coverage: One 80-lb bag covers 35-40 standard modular bricks

Bags needed: Total Mortar Volume (cu ft) ÷ 0.60 (coverage per 80-lb bag)

Cubic yards: Cubic Feet ÷ 27

About Brick Mortar Calculations

Accurate mortar calculation is critical for brick masonry projects to ensure adequate material supply, prevent work stoppages, control costs, and maintain consistent mortar color throughout the project. Mortar serves multiple essential functions: bonding bricks together, distributing loads evenly across the wall, sealing against water and air infiltration, accommodating minor dimensional variations in bricks, and providing aesthetic uniformity through consistent joint appearance. Standard 80-pound bags of pre-mixed mortar typically cover 35-40 standard modular bricks with 1/2-inch joints, though coverage varies significantly with brick size, joint thickness, mason skill, and application technique. Proper estimation prevents the common problem of running out of mortar mid-course, which creates visible color lines as new batches never match perfectly.

Mortar joint thickness significantly impacts material requirements and structural performance. Standard residential masonry uses 1/2-inch (0.5″) joints, providing optimal balance of coverage, strength, and water resistance. Thin joints at 3/8 inch (0.375″) are used in precision work with highly consistent brick dimensions, commercial applications, or contemporary aesthetic designs, reducing mortar consumption by 20-25% but requiring expert masonry skills. Thick joints at 5/8 inch (0.625″) appear in historic restoration matching original construction, applications with irregular handmade bricks, or specific architectural styles, increasing mortar needs by 20-30% over standard joints. Joint thickness affects not only material quantity but also wall strength, water penetration resistance, and overall appearance—thinner joints generally provide better structural performance while thicker joints accommodate dimensional variations.

Professional masons choose between pre-mixed bagged mortar and site-mixed mortar based on project size, budget, quality control needs, and specific requirements. Pre-mixed mortar in 80-pound bags costs $8-$15 each, requires only adding water, provides consistent quality batch after batch, and suits small to medium projects (under 1,000 bricks). Site-mixed mortar using separate portland cement ($10-$15 per 94-lb bag), hydrated lime ($12-$18 per 50-lb bag), and masonry sand ($25-$50 per cubic yard) reduces material costs by 30-50% on large projects over 2,000 bricks, allows custom color matching for restoration work, and provides greater control over workability and setting time. However, site mixing requires proper proportioning equipment, skilled mixing personnel, and careful quality control to maintain consistency across batches.

ASTM Mortar Type Selection Guide

  • Type N (General Purpose): Above-grade exterior walls, interior walls, non-load bearing applications. Medium strength (750 psi). Mix: 1 cement : 1 lime : 6 sand
  • Type S (High Strength): Below-grade walls, retaining walls, areas with high lateral loads or wind. High strength (1,800 psi). Mix: 1 cement : 1/2 lime : 4.5 sand
  • Type M (Maximum Strength): Heavy load-bearing walls, foundations, below-grade in contact with soil. Very high strength (2,500 psi). Mix: 1 cement : 1/4 lime : 3 sand
  • Type O (Low Strength): Interior non-load bearing walls, historic restoration. Low strength (350 psi). Mix: 1 cement : 2 lime : 9 sand

Frequently Asked Questions

How many bricks will one 80-pound bag of mortar lay?

One 80-pound bag of pre-mixed mortar typically lays 35-40 standard modular bricks (8″ × 3.625″ × 2.25″) with 1/2-inch joints. Actual coverage varies based on several factors: brick size (larger bricks require more mortar per unit), joint thickness (3/8″ joints increase coverage to 45-50 bricks, 5/8″ joints decrease to 30-35 bricks), mason skill and technique (experienced masons waste less), mortar consistency (wetter mixes spread further but weaker), and environmental conditions (hot weather increases evaporation and waste). For larger queen or king bricks, expect 28-35 bricks per bag. Smaller closure or engineer bricks may achieve 40-45 per bag. Always order 10-15% extra bags to account for waste, spills, learning curve, and mortar that hardens before use. For 500 bricks with standard joints, order 13-15 bags (500 ÷ 37 = 13.5 bags).

What is the difference between Type N, Type S, and Type M mortar?

Mortar types differ in compressive strength, cement-to-lime ratio, and appropriate applications per ASTM C270 standards. Type N (750 psi compressive strength) suits general above-grade exterior and interior walls, providing good workability, water retention, and bond strength for residential masonry. Type S (1,800 psi) offers higher strength for below-grade applications, retaining walls, manholes, sewers, and structures subject to high lateral loads or wind pressure. Type M (2,500 psi) delivers maximum strength for heavy load-bearing walls, foundations, driveways, and below-grade work in contact with soil. Higher strength mortars contain more cement and less lime, making them harder but less flexible—potentially causing brick cracking if bricks are softer than mortar. Match mortar strength to brick strength: use Type N with most face brick, Type S for engineering brick and challenging conditions, Type M only when specifically required by structural engineers for extreme loading conditions.

Should I use pre-mixed bagged mortar or mix my own from scratch?

Choose pre-mixed bagged mortar for small to medium projects (under 1,000-1,500 bricks), DIY applications, situations requiring consistent color, and jobs where convenience outweighs cost savings. Bagged mortar costs $8-$15 per 80-lb bag, requires only adding water, eliminates proportioning errors, and provides reliable quality. For large commercial projects over 2,000 bricks, site-mixed mortar from bulk cement ($10-$15 per bag), hydrated lime ($12-$18 per bag), and sand ($25-$50 per yard) reduces costs by 30-50%. Site mixing suits restoration projects requiring custom color matching, situations where specific mix ratios are needed, and jobs with experienced masons and proper mixing equipment. Calculate break-even: if your project needs more than 40-50 bags, site mixing probably saves money. However, quality control demands are higher—inconsistent batches create visible color variations and strength differences that compromise both appearance and structural integrity. For critical structural work, some specifications mandate bagged mortar for quality assurance.

How long does mixed mortar last before it hardens and becomes unusable?

Properly mixed mortar remains workable for approximately 90 minutes to 2 hours after initial mixing under normal conditions (70-80°F temperature, moderate humidity). Hot weather (above 85°F) or dry conditions reduce working time to 60-90 minutes as water evaporates faster. Cool weather (50-60°F) or humid conditions may extend working time to 2-3 hours. Once mortar begins to stiffen, never re-temper by adding water—this severely weakens the mortar, reduces bond strength, and creates durability problems. Instead, discard hardened mortar and mix fresh batches. Mix only what you can use within the working time: experienced masons typically mix 1-2 bags at a time depending on laying speed. For DIY projects, start with half-bag batches until you understand your consumption rate. Keep mortar covered when not actively in use to prevent evaporation. If mortar becomes too stiff to work but hasn't fully set, it's already compromised—don't use it for structural masonry even if you can still spread it.

What happens if I run out of mortar halfway through my brick project?

Running out of mortar mid-project creates visible color variations called "banding" or "coursing lines" where old and new mortar batches meet, even when using identical products. Mortar color varies slightly between production lots, mixing batches, water content, curing conditions, and age. To minimize this problem: order all mortar from the same production lot and manufacturer, purchase 15-20% extra beyond calculated needs, store bags in dry conditions, and plan stopping points at natural breaks (corners, openings, course heights) rather than mid-wall. If you must stop mid-course, thoroughly wet the last laid course before continuing, mix new mortar to match previous consistency exactly, and consider tooling joints differently to disguise the transition. For restoration work matching existing mortar, create test panels with various mix ratios, cure for several weeks, and compare under different lighting before proceeding. Some masons intentionally vary mortar color slightly across large walls to create natural-looking variation, but this requires expertise and artistic judgment to avoid obvious mistakes.

Related Brick Calculators

→ Brick Quantity Calculator - Calculate total bricks needed for your project→ Brick Cost Calculator - Estimate complete project costs→ Brick Wall Area Calculator - Calculate wall area with openings

Professional Mortar Mixing and Application Tips

  • Achieve peanut butter consistency: Mortar should stick to trowel at 90-degree angle without sliding off
  • Use clean potable water: Contaminated water weakens mortar and causes discoloration or efflorescence
  • Mix in proper sequence: Combine dry ingredients first, then add 3/4 water, mix, add remaining water gradually
  • Allow slake time: Let mortar rest 5-10 minutes after initial mixing for better workability
  • Never re-temper hardened mortar: Adding water to stiffened mortar severely reduces strength and bond
  • Work within temperature limits: Apply mortar only when temperatures are 40-90°F and will stay above freezing for 24-48 hours
  • Protect from weather: Cover fresh mortar joints from rain, direct sun, and freezing for 24-48 hours
  • Tool joints at proper time: Strike joints when mortar is thumbprint-hard (firm but not fully set) for best appearance and seal