Calculadora de Cimento Online Grátis
Cement bags, sand and aggregate for any mix ratio and volume
The Cement Calculator determines how many bags of cement and what quantities of sand and aggregate you need for a custom concrete or mortar mix, based on your chosen mix ratio (such as 1:2:4 or 1:3) and total volume required. It's used by masons, structural engineers, and builders who mix their own concrete on-site rather than using pre-mixed bags.
Frequently Asked Questions
Sobre Esta Calculadora
When mixing concrete or mortar on-site, the mix ratio controls both strength and workability. A 1:1.5:3 ratio (M20 grade) is suitable for structural elements like beams and slabs; a 1:2:4 ratio (M15) works for foundations and mass concrete; a 1:4 cement-to-sand ratio is standard for brickwork mortar. Getting the proportions wrong by even 10% affects final strength noticeably.
The calculator applies the dry volume factor (typically 1.54) that accounts for the voids between aggregate particles before mixing — a common source of error in manual estimates. It then breaks the result into separate quantities for each constituent material, expressed in both volume and weight for easy ordering.
Use this tool when you have specific mix ratio requirements from a structural engineer's specification, or when ready-mixed concrete is unavailable and you're batching by the bag or by the cubic metre with a site mixer.
A Calculadora de Cimento determina quantos sacos de cimento e qual a quantidade de areia e brita você precisa para uma mistura de concreto ou argamassa personalizada.
Exemplo Resolvido
Calculating materials for a 1:2:4 mix for 1 m³ of concrete
Entradas:
- Mix ratio: 1 part cement : 2 parts sand : 4 parts aggregate
- Volume required: 1 m³ (after compaction, use dry volume = 1.54 m³)
Passo a Passo:
- Total parts = 1 + 2 + 4 = 7
- Cement volume = (1/7) × 1.54 = 0.22 m³
- Convert to bags: 0.22 m³ ÷ 0.035 m³/bag = 6.28 → 7 bags of 50 kg cement
- Sand volume = (2/7) × 1.54 = 0.44 m³ (≈ 0.70 tonnes)
- Aggregate volume = (4/7) × 1.54 = 0.88 m³ (≈ 1.30 tonnes)