Concrete Mix Ratio Converter
Enter the three parts of your mix and the total quantity to split it into material amounts. Wet volume V = area × user volume per area × (1 + waste / 100). Cement = V / (s + 1); sand = V − cement. Whole bags = ceil(cement / user bag volume), computed exactly from decimal inputs. Both ratios are your independent scenarios for the same total volume. This partitions wet volume only; bag volume is your supplied conversion basis, not a dry-material yield, mass, shrinkage allowance, or recipe recommendation. No assumed 25 kg bag volume or ratio presets.
A QUICK WALKTHROUGH
How to use this tool
- Enter the ratio parts for cement, sand, and aggregate.
- Enter the total quantity in your chosen unit.
- Review each material share and the ratio total.
- Select mortar, enter area, wet volume per area, waste, primary and alternative sand ratios, and your bag volume; calculate and read both scenario rows.
Simple proportion arithmetic
This converter divides the total quantity according to the three parts you enter. It does not choose a recipe, material density, moisture correction, or unit conversion.
Planning estimate only
This is a volume or quantity estimate from a user supplied ratio and does not represent structural engineering mix design or a construction specification.
Two-part wet mortar partition
Wet volume V = area × user volume per area × (1 + waste / 100). Cement = V / (s + 1); sand = V − cement. Whole bags = ceil(cement / user bag volume), computed exactly from decimal inputs. Both ratios are your independent scenarios for the same total volume. This partitions wet volume only; bag volume is your supplied conversion basis, not a dry-material yield, mass, shrinkage allowance, or recipe recommendation. No assumed 25 kg bag volume or ratio presets.
User scenario comparison
Enter finite area, wet volume per area, waste and both sand ratios ≥ 0, and finite bag volume > 0. Bag counts must be safe whole numbers. Unsupported extreme precision, underflow, overflow and lost positive arithmetic are rejected. Inputs start blank.
Report (raw inputs and unrounded outputs)
Mortar units: area m²; volume rate m³/m²; waste percent; sand : cement dimensionless; bag volume m³/bag; result volumes m³ and whole bags. Concrete uses one consistent user-chosen unit.
GOOD TO KNOW
Common questions
Does it design concrete strength?
No. It only splits a total quantity according to your entered three-material ratio.
What units can I use?
Use any single unit consistently for the total and the three resulting amounts; the converter does not convert units.
What does the ratio mean?
The three parts are proportional shares for cement, sand, and aggregate, in that order.