Mortar Volume Calculator

Calculate mortar volume for planters, paths, and walls. Switch units, include waste, and compare bags. Export results to share with crews and suppliers quickly.

Use wall mode for garden walls and planters.
Switching units updates visible fields.
Covers spill, tool loss, and uneven joints.
Typical joint or mortar bed thickness.
Optional: vents, gaps, or inset planters.

Advanced options

These settings improve estimating, but they are optional.

Used for a simple parts-based volume split.
Use your product data if available.
Enter the volume produced per bag.
Any units you use; results match those units.

Calculation history

Your last 20 calculations stay in this browser session.

Timestamp Units Mode Net area Waste % Volume (m³) Volume (L) Volume (ft³) Bags
No calculations yet. Run one above to populate this table.

Example data table

Sample scenarios for garden planters and edging. Replace values with your project dimensions.

Scenario Mode Inputs Thickness Waste Estimated volume
Brick planter face Wall Length 3.0 m, Height 0.6 m 10 mm 8% 0.0194 m³ (19.4 L)
Stone edging bed Area Area 4.0 m² 12 mm 10% 0.0528 m³ (52.8 L)
Low garden wall Wall Length 18 ft, Height 2 ft 0.5 in 12% 1.68 ft³ (0.0476 m³)
Examples are illustrative. Always verify with your material supplier.

Formula used

The calculator estimates mortar as a simple volume:

  • Base area = Length × Height (wall mode) or Area (area mode)
  • Net area = Base area − Openings
  • Thickness is converted to meters or feet
  • Volume = Net area × Thickness
  • Waste-adjusted volume = Volume × (1 + Waste%/100)

Bag counts use your provided bag yield: Bags = Total volume ÷ Yield per bag.

How to use this calculator

  1. Select a calculation mode: wall (L×H) or area.
  2. Pick your unit system and enter dimensions.
  3. Enter mortar thickness and optional openings to subtract.
  4. Add a waste percentage that fits your working conditions.
  5. Optional: set bag yield to estimate bags and water.
  6. Press Calculate to see results above the form.
  7. Use CSV or PDF buttons to save or share outputs.

Project scope and measurement

Accurate mortar estimating reduces delays, waste, and mismatch between batches. Measure the surface receiving mortar, choose wall mode for length and height, or area mode for flat beds. Subtract openings like vents, inset planters, or large gaps. Record dimensions from the finished face, not the block size, to better reflect real coverage. For stepped beds, calculate each section separately, then sum totals.

Thickness and joint control

Thickness drives consumption more than most people expect. A change from 10 mm to 12 mm increases volume by 20% at the same area. For bedding under stone or pavers, base thickness on your screed guides or typical trowel build. For pointing, base it on average joint width and depth, and keep application consistent across sections. If thickness varies for leveling, use an average based on several spot checks.

Waste allowance and site factors

Waste factors usually range from 5–15%. Tight work with controlled mixing and clean substrates can stay near 5–8%. Irregular stone, hot weather, wind, or repeated re-tempering can increase loss. Use a higher allowance when you expect extra trimming, frequent tool cleaning, or interruptions that force partial batches to be discarded. Pre-damping porous masonry can improve adhesion and reduce rapid water loss.

Bag planning and handling logistics

Bag yield varies by product and water content, so rely on packaging data when available. Enter yield per bag to estimate bags, then round up to avoid running short. The density field provides a weight estimate for lifting and transport, useful when staging materials in a garden with limited access. Weight estimates also help plan wheelbarrow trips and lifting limits.

Batch consistency and mix breakdown

Consistent batches improve color and workability, especially on visible planter faces and edging. Use the mix ratio option to split total volume into cement and sand parts for purchasing bulk materials. This allocation is parts-based and not a structural design mix. Follow manufacturer guidance for water, additives, curing time, and temperature limits for outdoor durability.

FAQs

1) What thickness should I use for garden masonry?

Use your planned joint or bed thickness. Common values are 8–12 mm for brickwork joints and around 10–15 mm for bedding, but verify your method and materials.

2) Why does the calculator ask for a waste percentage?

Waste accounts for spill, tool loss, uneven joints, and leftover mortar that cannot be used. A realistic allowance reduces the risk of running short mid-job.

3) How do I subtract openings correctly?

Measure the areas that will not receive mortar, such as vents, large gaps, or inset planters. Enter the total opening area, and the calculator subtracts it from the base area.

4) Are bag yields the same for every mortar product?

No. Yield depends on the formulation and water content. Use the yield printed on the bag or technical sheet, then enter it to estimate bag count accurately.

5) Does the mix ratio section design a structural mortar?

No. It only splits the total volume by parts to help plan cement and sand quantities. Follow local practice and manufacturer guidance for strength and durability.

6) Should I round up the number of bags?

Usually yes. Rounding up avoids delays from shortage and covers small measurement errors. Unopened bags can often be stored for later work if kept dry.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.