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Construction & HomematerialsIndia only

Sand Quantity Calculator

Sand for a concrete or mortar mix, including the bulking allowance. Damp sand occupies substantially more volume than dry sand, so ordering by the mix figure alone leaves you short.

Also called: sand quantity for concrete, sand bulking.

%
Sand to order (m³)
1.51

1.51 m³ once the 20% bulking allowance is added to the 1.26 m³ the mix needs. That is about 2.42 tonnes, or 53.4 cubic feet.

Sand the mix needs (m³)
1.26
Approximate tonnes
2.42
In cubic feet
53.4
Tractor loads at 2.8 m³
0.54
Dry volume (m³)
4.62
How this is calculated
Method and background

How this is calculated

Take the dry volume, split off the sand share of the mix ratio, then add for bulking. Bulking is the one that surprises people: sand with a few percent moisture can occupy twenty to thirty percent more volume than the same sand dry, because surface tension holds the grains apart. Since sand is sold by volume and used by the mix ratio, the allowance is real money.

sand = wet volume * dry factor * sand share of the mix, plus a bulking allowance
b
Sand parts (parts)
total parts
Sum of the mix parts (parts)
u
Bulking allowance (decimal)

Worked examples

Each of these is asserted on every build. If a change to the engine ever moved one of these answers, the build would fail before the page could print it.

M20 sand for one cubic metre

Concrete or mortar volume (m³)
1
Sand parts in the mix
1.5
Total parts in the mix
5.5
Dry volume factor
1.54
Bulking allowance for damp sand
20%

Sand to order (m³)0.5

1.54 * 1.5 / 5.5, then a fifth added for bulking

Open this example

dry sand needs no allowance

Concrete or mortar volume (m³)
1
Sand parts in the mix
1.5
Total parts in the mix
5.5
Dry volume factor
1.54
Bulking allowance for damp sand
0%

Sand to order (m³)0.42

boundary

Open this example

Method and limits

What it assumes

  • A nominal mix by volume, and sand delivered damp as it usually is.

What it deliberately does not model

  • Bulking peaks around four to six percent moisture and falls away when the sand is saturated, so the allowance is a range rather than a constant.
  • Tonnage assumes about 1.6 tonnes per cubic metre, which varies with grading.

Sources

Formula version 1.0.0 · definition 1.0.0 · India · Report a problem with this calculator

Frequently asked questions

What is sand bulking?
Moisture films hold sand grains apart, so damp sand takes up more room than the same mass dry. The effect peaks at a few percent moisture and can add a quarter to the volume.