Find how much compost to spread over a garden bed.
Spreading a layer of compost over a bed multiplies the surface area by the chosen depth to give the volume needed. A thin top dressing feeds the soil food web without burying stems, so matching depth to volume prevents over- or under-applying.
Bed Compost Volume
Compost volume = area x depth; a 1 to 3 inch top dressing is typical
Compost volume = area x depth; a 1 to 3 inch top dressing is typical Spreading a layer of compost over a bed multiplies the surface area by the chosen depth to give the volume needed.
A thin top dressing feeds the soil food web without burying stems, so matching depth to volume prevents over- or under-applying.
This calculator takes 3 inputs: Bed length, Bed width, Compost depth. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.