1:2:3 Concrete Mix Calculator
This 1:2:3 concrete mix calculator converts a target concrete volume into the materials to batch it: cement (in 50 kg bags), sand and coarse aggregate, plus a water estimate at a 0.5 water-cement ratio.
Comment utiliser ce calculateur
- Saisissez vos dimensions — pieds pour les longueurs, pouces pour l'épaisseur.
- Ajustez les options — pourcentage de perte, taille du sac et prix local du béton.
- Lisez vos résultats — le volume, les sacs, le poids et le coût se mettent à jour en direct.
La formule
Dry volume = wet volume × 1.54, split in 1:2:3 proportions by volume Exemple résolu : For 1 m³: dry volume 1.54 m³ ÷ 6 parts = 0.257 m³ cement (≈ 8 × 50 kg bags), 0.513 m³ sand, 0.770 m³ gravel.
The 1:2:3 mix (1 part cement, 2 parts sand, 3 parts gravel — general construction) is batched by volume: for every bucket of cement, add two of sand and three of gravel. It's the classic general-purpose mix — slabs, footings, walks — reaching about 3,000 psi.
The 1.54 dry-volume factor matters: mixed concrete compacts, so you need about 54% more loose dry material than the finished volume. Skipping this factor is the classic under-order in hand batching.
Batch consistently — use the same bucket or gauge box for every part, keep the water-cement ratio near 0.5 (about 25 litres per 50 kg cement bag), and mix full bags of cement to avoid weighing errors.
Foire aux questions
Questions courantes sur le 1:2:3 concrete mix calculator.
What is a 1:2:3 concrete mix?
Parts by volume — 1 part cement, 2 parts sand, 3 parts gravel — general construction. for every bucket of cement, add two of sand and three of gravel. It's the classic general-purpose mix — slabs, footings, walks — reaching about 3,000 psi.
How strong is a 1:2:3 mix?
With a 0.5 water-cement ratio, roughly 3,000 psi (≈ 20 MPa / M20 class) at 28 days — suitable for most residential work.
How much water do I add?
Target a 0.5 water-cement ratio: about 25 litres per 50 kg bag of cement. Add most of the water first, then trim to a workable, not soupy, consistency.
Why multiply by 1.54?
Loose cement, sand and aggregate contain air voids that close up when mixed and compacted — 1 m³ of finished concrete consumes about 1.54 m³ of loose dry ingredients.
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