Concrete Volume Calculator
Volume and rough cement/ready-mix estimates
Inputs
Industry standard is 5–10% for concrete. Set to 0% if ordering exact volume.
Note: Cement bag and ready-mix tonne estimates are approximate (mix design and density vary).
Results
Enter your dimensions then click Calculate.
UKUK Building Regulations
References & Sources
Standards Cited
- BS 8500-1 — Concrete — Complementary British Standard to BS EN 206 — Method of specifying and guidance for the specifier
Defines concrete strength classes and specifying requirements for UK construction - BS EN 206 — Concrete — Specification, performance, production and conformity
European standard for concrete specification, including ready-mix density and volume calculations
Formulas Used
- Concrete volume:
volumeM3 = length x width x depth x (1 + wastage% / 100)
Source: Basic geometry — Wastage defaults to 0% for backward compatibility; industry standard is 5-10% - Unit conversion (m3 to yd3):
volumeYd3 = volumeM3 x 1.308
Source: Standard unit conversion - Unit conversion (m3 to ft3):
volumeFt3 = volumeM3 x 35.315
Source: Standard unit conversion - Cement bags estimate:
bags25kg = ceil(volumeM3 x 12); bags50kg = ceil(volumeM3 x 6)
Source: BS 8500-1 (1:2:4 mix ratio) — Based on ~300 kg cement per m3 for a typical 1:2:4 mix - Ready-mix weight:
readyMixTons = volumeM3 x 2.4
Source: BS EN 206 — Ready-mix concrete density approximately 2400 kg/m3
Key Assumptions
- Ready-mix concrete density: 2400 kg/m3 — BS EN 206
- Cement bag estimate based on typical 1:2:4 mix ratio (~300 kg cement per m3 = 12 x 25kg bags) — BS 8500-1
- Wastage allowance defaults to 0% but 5-10% is recommended for site-mixed or ready-mix concrete — Industry standard practice