About this calculator
This calculator converts between tonnes and cubic metres for sand, gravel, crushed stone or topsoil, and works out how many truck loads a delivery needs. Enter the material by area and spread depth, by a direct volume, or by a direct mass — whichever you already know — and it fills in the rest.
Formula
area x depth: volume = length x width x depth
volume given: mass = volume x density / 1000
mass given: volume = mass x 1000 / density
trucks by volume = ceil(volume / truck volume capacity)
trucks by mass = ceil(mass / truck mass capacity)
truck loads needed = the larger of the two
Worked example
A 10 x 5 m area spread 100 mm deep with sand (1600 kg/m³), delivered in 2 m³ / 10 t trucks.
volume = 10 x 5 x 0.1 = 5 m³
mass = 5 x 1600 / 1000 = 8 t
trucks by volume = ceil(5 / 2) = 3
trucks by mass = ceil(8 / 10) = 1
truck loads needed = 3 (limited by volume)
FAQ
Why does the truck count check both volume and mass? A truck (or a container) can fill up by volume before it reaches its legal weight limit — common for light, bulky material like topsoil — or reach its weight limit while its bed still looks half-empty — common for dense material like crushed stone. This calculator checks both limits and reports whichever needs more loads.
Which bulk density should I use? The one printed on your supplier's delivery note or product data sheet, if you have it — bulk density varies with moisture content and how tightly the material has settled. The defaults here are rough, commonly-quoted examples, not measurements of your specific load.
Why three different input modes? Different jobs start from different known quantities — a footprint and a target depth, a volume already quoted by a supplier, or a delivery weight already on an invoice. Each mode lets you enter what you actually have and get the other two figures from it.
Which standard does this follow? None is cited. Converting between volume and mass via a stated density is plain physics, not a standard; bulk density figures themselves are supplier data, not code values.
Assumptions and limits
Bulk densities and truck capacities (both the volume and the mass limit) are all user inputs with example defaults, not data for a specific supplier or vehicle. No drawing is produced — the result is a volume/mass conversion and a truck-load count only.