Inputs
Change units to match your project drawings.
m³
Direct volume. Use helper below if you need to calculate it.
Volume helper (single element)
Rectangular element: length × width × thickness
m
m
m
Computed: 0.180 m³
Nominal mixes mapped to common site proportions.
:
:
Edit when “Custom ratio” is chosen.
Typical structural mixes fall in 0.40–0.55.
Accounts for voids and bulking when batching by volume.
Bulk densities (editable)
kg/m³
kg/m³
kg/m³
Corrections
Adds a contingency to all materials.
kg
Default 50 kg (or 94 lb in US).
Calculated materials
Cement
0 kg
0.00 bags
Sand
0 kg
Adj. vol: 0 m³
Aggregate
0 kg
Volume: 0 m³
Mix water
0 L
Required: 0 L
| Component | Dry volume | Adjusted volume | Dry mass | Wet mass |
|---|
Notes: Wet mass includes moisture; sand adjusted for bulking; all items include wastage contingency.
Example outputs per 1 m³ (defaults)
| Mix | C:S:A | Cement (kg) | Sand (kg) | Aggregate (kg) | Water (L) | Bags (50 kg) |
|---|
How to use
- Select the unit system matching your drawings.
- Enter total concrete volume or compute it using the helper.
- Choose a nominal mix or set a custom ratio.
- Verify densities and the dry volume factor for your materials.
- Set w/c, moisture, bulking, and wastage according to site conditions.
- Press Calculate, then export CSV or PDF.
Formula used
// 1) Dry volume:
DryVolume = WetVolume × DryFactor
// 2) Ratio split (C:S:A = rC:rS:rA):
Sum = rC + rS + rA
Vol_C = DryVolume × rC / Sum
Vol_S = DryVolume × rS / Sum
Vol_A = DryVolume × rA / Sum
// 3) Convert to dry mass using bulk densities (ρ):
Mass_C_dry = Vol_C × ρ_C
Mass_S_dry = Vol_S × ρ_S
Mass_A_dry = Vol_A × ρ_A
// 4) Moisture & bulking:
Mass_S_wet = Mass_S_dry × (1 + Moist_S%)
Mass_A_wet = Mass_A_dry × (1 + Moist_A%)
Vol_S_adj = Vol_S × (1 + Bulking_S%)
// 5) Wastage:
All quantities × (1 + Wastage%)
// 6) Bags:
Bags = Mass_C_dry / BagSize
// 7) Water:
WaterRequired = w/c × Mass_C_dry // kg ≈ liters
WaterFromMoisture = (Mass_S_wet - Mass_S_dry) + (Mass_A_wet - Mass_A_dry)
WaterToAdd = max(0, WaterRequired - WaterFromMoisture)
FAQs
A common range is 0.40–0.55 for general structural work, balancing strength, durability, and workability. Lower ratios increase strength but may reduce workability without admixtures.
When batching by volume, voids between particles and bulking of sand require extra “dry” volume above the wet concrete volume. The factor 1.50–1.60 is often used on site conditions.
Moisture increases wet mass and contributes water to the mix; bulking inflates sand’s measured volume. This tool adjusts water and volumes so target proportions are maintained.
Nominal mixes use fixed proportions (e.g., 1:2:4). Design mixes are engineered to meet specific strengths, exposure, and workability, often requiring laboratory trials and codes compliance.
It focuses on batching quantities. Reinforcement, slump, admixtures, and curing are project-specific; adjust w/c and consult specifications or lab trials for fresh properties.
It depends on the mix ratio and dry factor. For 1:2:4 with default settings, cement is about 403 kg, which is roughly 8.06 bags per cubic meter.