Concrete Calculator

Written byOleh Soloninupdated 25 September 2026

Element

Length, m

Width, m

Thickness or height, m

How many

Sand per part of cement

Parts by mass from the mix design or from the cement bag. 1 : 2 : 4 is an example.

Gravel per part of cement

Water-cement ratio

0.5 is an example. Aggregate on site is wet, and that water is taken off the batch (GOST 27006-2019).

Advanced options

Mean density of the concrete, kg/m³

Heavy concrete under GOST 26633-2015 runs from above 2000 up to 2500 kg/m³.

Cement bag weight, kg

Spare, %

Result

Volume, m³2.4
With spare, m³2.52
Cement per m³, kg320
Cement in total, kg768
Bags of cement16
Sand, kg1,536
Gravel, kg3,072
Water, l384
How it was calculated
10 × 0.4 × 0.6 × 1 = 2.4 m³ parts 1 : 2 : 4 with a water-cement ratio of 0.5 make 7.5 parts; 2,400 ÷ 7.5 = 320 kg of cement per m³ 320 × 2.4 = 768 kg of cement, 16 bags of 50 kg

From dimensions to bags of cement

Concrete volume for a slab, strip footing or piles, broken down into cement, sand, gravel and water by the parts and density you set.

The volume of concrete is geometry: a 10 × 0.4 × 0.6 m strip footing is 2.4 m³, and twelve 0.3 m piles 2 m deep are 1.696 m³. That part the calculator gets exactly right, and it is the number you give when ordering ready-mix.

The mix is a different matter. Russian standard GOST 27006-2019 describes designing a mix for the actual cement, sand and aggregate rather than reading a grade off a table. So the proportions and the water-cement ratio are input fields: the calculator splits the mass of a cubic metre into cement, sand, gravel and water in the parts you set.

How to use

Pick the shape: a slab or strip takes length, width and thickness; a column or pile takes diameter and height.
Enter the dimensions and how many elements there are — the volume appears at once.
Set the parts of sand and gravel per part of cement, the water-cement ratio and the mean density, and read the mass breakdown.

Volume and mix for typical pours

Every row is a separate run of this calculator. Parts are 1 : 2 : 4 by mass, the water-cement ratio 0.5 and the density 2,400 kg/m³ unless stated otherwise.

Every value was produced by the calculator on this page.
Pour	Volume	Cement per m³	Cement	50 kg bags	Sand	Gravel	Water
Strip 10 × 0.4 × 0.6 m	2.4 m³	320 kg	768 kg	16	1,536 kg	3,072 kg	384 l
Slab 6 × 4 m, 10 cm	2.4 m³	320 kg	768 kg	16	1,536 kg	3,072 kg	384 l
12 piles ⌀0.3 m × 2 m	1.696 m³	320 kg	542.9 kg	11	1,085.7 kg	2,171.5 kg	271.4 l
Strip, parts 1 : 3 : 5	2.4 m³	252.6 kg	606.3 kg	13	1,818.9 kg	3,031.6 kg	303.2 l
Strip, w/c 0.45, density 2,450	2.4 m³	328.9 kg	789.3 kg	16	1,578.5 kg	3,157 kg	355.2 l

Why there is no grade-to-cement table here

Because there is none in the standards either. GOST 27006-2019 sets out mix design: a nominal mix is calculated and checked with trial batches for the cement, sand and aggregate actually on site, then converted into a working mix corrected for the moisture the aggregate carries — sand from a yard is never dry, and that water comes off the batch water.

So the calculator does not ask for a grade and does not check strength. The proportions are yours, from a mix design, the drawings or the cement bag. You can see what they do: at 1 : 3 : 5 a cubic metre holds 252.6 kg of cement instead of 320 kg, with more sand and gravel instead.

Where the mass of a cubic metre comes from

From the density. GOST 26633-2015 defines heavy concrete as concrete with a mean density above 2,000 and up to 2,500 kg/m³, and the calculator only accepts values in that range. The mass is then split into parts: 1 of cement, 2 of sand, 4 of gravel and 0.5 of water — 7.5 parts in all, so 2,400 ÷ 7.5 = 320 kg of cement.

The same arithmetic shows what a lower water-cement ratio does: at 0.45 and a density of 2,450 kg/m³ a cubic metre takes 328.9 kg of cement and the 2.4 m³ pour takes 355.2 litres of water. How strong the concrete turns out is a question for test cubes, not for this page.

What this calculator shows

Volume, and the same figure with a five percent allowance
Cement by mass and by 50 kg bags
Sand, gravel and water in the same proportions

What to keep in mind

The 1 : 2 : 4 parts by mass are a default example, not a designed mix: take your own from a mix design, the drawings or the bag.
The volume of reinforcement is not deducted, so the figure is slightly more concrete than the pour will hold. There is no grade field: a calculation cannot confirm the strength of a mix.

FAQs

How much concrete for a 10 m strip footing?

At 0.4 m wide and 0.6 m deep, 2.4 m³ — 2.52 m³ with a 5% allowance. How many deliveries that takes depends on the drum size, which the supplier will tell you.

How much cement is in a cubic metre?

Whatever your parts and density imply: at 1 : 2 : 4 with a water-cement ratio of 0.5, a 2,400 kg cubic metre holds 320 kg of cement. No standard table maps a grade onto a cement figure; the mix is designed.

How much for piles?

One pile is the area of the circle times the depth: 0.3 m across and 2 m deep is 0.1414 m³. Twelve piles are 1.696 m³, which takes 542.9 kg of cement — eleven 50 kg bags.

What is the water-cement ratio?

The mass of water divided by the mass of cement. Lower means stronger and denser concrete but a stiffer mix. It is a field here: at 0.45 instead of 0.5 a cubic metre takes more cement and less water.

Can I just copy a mix from the internet?

Not safely: a mix belongs to its materials — the strength class of the cement, the grading and the moisture of the sand and gravel. GOST 27006-2019 requires the nominal mix to be corrected for that moisture before it is batched.

Which density should I enter?

For ordinary heavy concrete, 2,000 to 2,500 kg/m³ as GOST 26633-2015 defines it; the default is 2,400. Values outside that range are rejected: they describe lightweight or special heavyweight concrete with rules of their own.

Worked example

A strip footing

Input: 10 × 0.4 × 0.6 m, parts 1 : 2 : 4, w/c 0.5, density 2,400 kg/m³

Output: 2.4 m³ of concrete, 768 kg of cement, 16 bags of 50 kg

Note: Plus 1,536 kg of sand, 3,072 kg of gravel and 384 litres of water; with a 5% allowance the volume is 2.52 m³.

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