Use this concrete mix calculator after the required finished volume is known. Published mode scales a cited 1:2:4 material schedule with no hidden extra volume; custom mode starts with a measured cement volume and scales only the sand and coarse-aggregate volumes by the entered dry-parts ratio.
What a 1:2:4 mix means
The ratio names cement, sand, and coarse aggregate in that order. Published mode scales the cited schedule; it does not infer a strength class.
Worked example
- For 1 with 0% extra volume, the cited schedule gives 320 cement, 0.47 sand, 0.705 coarse aggregate, and 205 reference water.
- With 50 bags, 320 ÷ 50 rounds up to 7 bags.
Published materials for 1 m³
The default schedule is 320 cement, 0.47 sand, 0.705 coarse aggregate, and 205 reference water per cubic metre. Any visible extra-volume percentage scales every listed quantity together.
Why water and strength still need project control
The reference-water result reports the cited schedule, not a universal instruction. Aggregate moisture, grading, workability, admixtures, proportioning, production, curing, and testing control the actual batch and its verified performance.
Frequently asked questions
What does a 1:2:4 concrete mix mean?
It names one part cement, two parts sand, and four parts coarse aggregate in that order. On this page, the default result scales a cited 1:2:4 material schedule rather than pretending seven loose parts equal a known finished yield.
How much cement is needed for 1 of 1:2:4 concrete?
The published schedule used here specifies 320 of cement per cubic meter, along with 0.47 of sand and 0.705 of coarse aggregate. Seven 50 bags are required because bags round up.
Does a 1:2:4 ratio guarantee concrete strength?
No. Strength and durability depend on material properties, water content, proportioning, production, curing, and verification. Use the project mix design and specification when performance matters.