Mortar Mix Ratio Calculator
Split a planned mortar volume into cement, sand and lime components using adjustable mix parts, dry-volume factor, bag yields and prices.
Default project preview
29.26 ft³
Cement bags
6
Sand volume
0.79 yd³
Lime bags
3
Cement volume
5.32 ft³
Calculator
Build the material order
Your order will appear here
Enter the project details and calculate a rounded material estimate.
Input and output guide
What each value means
The labels and units below are part of this calculator’s visible methodology. Replace every default with measurements or product data from the actual project.
Finished mortar volume
Enter this project assumption in ft³. The current imperial default is 20 ft³.
Cement parts
Enter this project assumption in parts. The current imperial default is 1 parts. Minimum: 0.
Sand parts
Enter this project assumption in parts. The current imperial default is 4 parts. Minimum: 0.
Lime parts
Enter this project assumption in parts. The current imperial default is 0.5 parts. Minimum: 0.
Dry-volume factor
Enter this project assumption in factor. The current imperial default is 1.33 factor.
Waste allowance
Enter this project assumption in %. The current imperial default is 10 %. Minimum: 0. Maximum: 50.
Cement volume per bag
Enter this project assumption in ft³. The current imperial default is 1 ft³.
Lime volume per bag
Enter this project assumption in ft³. The current imperial default is 1 ft³.
Price per cement bag
Enter this project assumption in a unitless value. The current imperial default is 14. Minimum: 0.
Price per lime bag
Enter this project assumption in a unitless value. The current imperial default is 12. Minimum: 0.
Sand bulk price
Enter this project assumption in per yd³. The current imperial default is 55 per yd³. Minimum: 0.
How to read the outputs
Cement bags
rounded full bags. Default preview: 6.
Sand volume
bulk component. Default preview: 0.79 yd³.
Lime bags
rounded full bags. Default preview: 3.
Cement volume
ratio share. Default preview: 5.32 ft³.
Lime volume
ratio share. Default preview: 2.66 ft³.
Batch material cost
entered bag and sand prices. Default preview: $163.35.
Methodology
Transparent calculation
BuildMeter converts every input to a consistent internal unit, applies the selected allowance, and rounds products up to whole purchasable units.
Dry batch volume = finished volume × dry-volume factor × waste factor. Each ingredient volume equals dry batch volume × its parts ÷ total parts.
Reviewed project guidance
How to use this estimate in a real project
Last reviewed: July 30, 2026
Convert a selected volumetric mix ratio and target batch volume into component quantities for planning and comparison.
Calculation steps
- 1Enter the actual project dimensions or operating values.
- 2Apply the calculator formula using consistent units.
- 3Review the unrounded result and the editable allowance.
- 4Round only to the product, stock length or equipment increment actually purchased.
Worked numerical example
For a 1:1:6 cement-lime-sand ratio totaling 8 buckets, use 1 bucket cement, 1 bucket lime and 6 buckets sand.
Purchasing and rounding
Use the ratio to proportion components consistently by volume for trial or planning batches, but buy cement, lime and sand in their actual package or bulk units. For specified masonry work, use the mortar type and proportioning method required by the project rather than changing ratios to consume leftover material.
Interpret the result
The output shows component shares of the selected volumetric ratio; it does not predict hardened mortar strength from the ratio alone. Sand moisture, measuring method, mixing water, materials and specification requirements all affect the finished mortar.
Page-specific assumptions
- Inputs describe one consistent project condition.
- Entered yields and efficiencies match the selected product or equipment.
- Site-specific code and engineering requirements are checked separately.
Common mistakes
- Mixing imperial and metric inputs.
- Using nominal dimensions where actual coverage controls.
- Rounding intermediate values too early.
- Treating a quantity estimate as design approval.
Primary and technical references
BuildMeter provides planning estimates, not engineering, architectural, electrical, mechanical, plumbing, permit or code approval. Review the methodology and verify final decisions with product documentation and qualified professionals.
FAQ
Mortar Mix Ratio Calculator questions
Why is dry volume larger than finished mortar volume?+
Loose dry ingredients contain void space and compact when mixed, so an adjustable dry-volume factor is included.
Do the parts need to total a specific number?+
No. The calculator normalizes any positive relative parts automatically.
Can one mortar ratio be used everywhere?+
No. Required mortar type and proportions depend on masonry, exposure, loading and specification.