Calculating gravel in volume and weight

Like any other bulk material, we define gravel in density, which assigns a fixed weight to a solid volume. From this figure of kilogram or ton to one cubic meter, the weight of the necessary amount needed to fill a gravel surface can be calculated.

Tolerances due to fracture forms

Gravel with its grain sizes of 32 to 63 millimeters consists of relatively large single fragments. Since in the construction industry ballast is defined as exclusively broken stone, the density of the loose ballast can vary the density more than with smaller grains such as chippings.

The irregular fracture forms of the ballast can tilt the grains or "lock" each other. This leads to larger voids between the grains and to a lower weight in a defined space. As a guideline for the density of the ballast, an average of 1.75 tonnes per cubic meter is calculated.

On average, the density of gravel is higher than that of gravel and lower than most gravel sites. Simply by moving a loose bulkhead, the density can be changed by five to ten percent.

How to calculate gravel

1. Define layer height

With gravel, you must expect greater tolerances than with smaller grained bulk materials. The more irregular and angular the individual breakage of the grains, the lower the density. A gravel layer that is opaque to the ground must be at least 15, better than 20 centimeters thick.

2. average value

To calculate, use the commonly used average of 1.75 tonnes per cubic meter, if it is a pure gravel grain with no chipped or fractured sand portions.

3. Calculate volume

Calculate the volume of the room to be filled by multiplying the length, width and height.

4. Calculate weight

Convert the density measurement unit from 1.75 tons to 1750 kilograms per cubic meter and multiply your result of the volume by the density. The result gives you the weight of your ballast in kilograms.

Tips & Tricks

Gravel can be less well and finally compact than smaller grained bulk material. Without a professional vibrating machine, you must expect subsequent sagging, especially on gravel surfaces subject to heavy traffic.