Mortar Calculator — Cement, Sand & Water for Masonry
Enter the area, mortar thickness, and mix ratio (cement:sand) to get the exact quantities of cement bags, sand, and water needed for your masonry project.
m²
mm
Mix ratio (cement : sand)
%
25 kg bags of Portland cement at 1440 kg/m³ bulk density
1:4
mix ratioCement
18%
Sand
72.1%
Water
9.9%
- 1
Mortar volume
10 × 0,012 × 1,1 = 0,132Area × depth in metres × waste factor. - 2
Dry ingredient volume
0,132 × 1.30 = 0,1716 - 3
Cement volume
0,1716 ÷ (1 + 4) = 0,0343Dry volume divided by total mix parts (1 cement + sand parts). - 4
Cement weight
0,0343 × 1440 kg/m³ = 49,42 - 5
Cement bags
⌈49,42 ÷ 25⌉ = 2Rounded up to whole 25 kg bags.
Kā darbojas šis kalkulators?
Masonry mortar volume = area × depth × (1 + waste%). Multiply by 1.30 for dry ingredient volume, then split by mix ratio: cement = dry/(1+r), sand = dry×r/(1+r). Water ≈ 0.55× cement by volume. Cement bags = ceil(kg / 25), where kg = cement m³ × 1440. A 1:4 ratio suits most bricklaying; 1:3 for structural work, 1:5–1:6 for render.
Formula
How this is calculated
Masonry mortar is a mix of Portland cement, building sand, and water — no coarse aggregate (which distinguishes it from concrete). The first step is to find the net mortar volume: area (m²) × joint depth (converted to m) × waste factor. The waste factor accounts for spillage and uneven surfaces; 10% is a typical default.
Because dry cement and sand compact on mixing, you need more dry material than the finished mortar volume. This calculator uses an empirical "dry volume factor" of 1.30 — that is, 1.30 m³ of dry ingredients yields roughly 1 m³ of mortar. The dry volume is then split according to the cement:sand ratio: cement = dry ÷ (1 + ratio) and sand = dry × ratio ÷ (1 + ratio). Water volume is estimated at 0.55× the cement volume by volume (a typical water/cement ratio for workable mortar).
Cement bag count uses a bulk density of 1440 kg/m³ for ordinary Portland cement (OPC) and standard 25 kg bags; adjust if local bags differ. All quantities are estimates — actual consumption varies with the skill of the mason, surface texture, ambient temperature, and exact aggregate grading. Always buy 10–15% extra to allow for waste.
Biežāk uzdotie jautājumi
A 1:4 mix (one part cement to four parts sand) is the most common general-purpose mortar for bricklaying and blockwork. It balances strength with flexibility. Use 1:3 for structural applications and 1:5 or 1:6 for renders and lightly loaded pointing.
First multiply the mortar volume by 1.30 to get the required dry ingredient volume (to account for mixing yield). Divide by (1 + sand ratio) to get cement volume, multiply by the cement bulk density (≈ 1440 kg/m³) for the weight in kilograms, then divide by 25 for 25 kg bags. The calculator does all of this automatically.
No — this calculator is for masonry mortar (cement + sand + water). For tile adhesive (thin-set) and grout use the Mortar & Grout Calculator; for concrete (cement + sand + gravel) use the Cement or Concrete Calculator.
Pazīstams arī kā
TG we-Calculate Editorial Team. (2026). Mortar Calculator — Cement, Sand & Water for Masonry [Online calculator]. TG we-Calculate. https://we-calculate.com/lv/calculator/mortar-calculator
TG we-Calculate Editorial Team. "Mortar Calculator — Cement, Sand & Water for Masonry." TG we-Calculate. 2026. https://we-calculate.com/lv/calculator/mortar-calculator.
TG we-Calculate Editorial Team, "Mortar Calculator — Cement, Sand & Water for Masonry," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/lv/calculator/mortar-calculator
@misc{wecalculate_mortar_calculator, title = {Mortar Calculator — Cement, Sand & Water for Masonry}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/lv/calculator/mortar-calculator}}, year = {2026}, note = {TG we-Calculate} }
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