If you are looking at buying a lot of compost for your garden then you might have been tempted by just buying a big bulk bag, I know I have many times. But is this actually a good deal, how many litres of compost do you get in a tonne bag?
How Many Litres of Compost Are In A Tonne Bag
The weight of compost will change massively depending on how dry it is which makes it impossible to compare the two on their own.
When is a Tonne Bag Not A Tonne?
Another factor to bear in mind is that a tonne bag of compost is rarely actually a tonne. A metric tonne is 1000kg but this is not usually the case for tonne bags of compost.
What has happened is that a tonne bag has become the generic name for a big bulk bag of compost rather than meaning there is actually a 1000kg in it.
For most composts, a 1000kg would actually require a huge bag and be much bigger than the bulk bags often delivered by builders’ merchants.
This tonne bag not a tonne bag debacle actually helps us out here though if we dig deeper. if you look on most landscaping supply sites now for a bulk bag of compost you will find that they actually show the volume of compost rather than saying it is a tonne bag.
This is probably a trading standards thing I would imagine and actually helps us out as regular gardeners. This allows us to compare getting a bulk bag to buying regular compost bags and see if we actually are getting a good deal.
So it is a good deal?
This would depend on the compost and the quality of it. but if you are just looking for volume rather than quality then often bulk bags aren’t that much of a good deal.
Let’s do a little maths to work this out.
I just went on Wickes for this to make the calculations simple. Their bulk backs of compost are 730L and priced between £120 and £135 depending on the type, these prices are true at the time of writing 23/05/2022.
That works out at 16 – 18 pence per litre of compost. If we now look at bags Wickes sells a 100L bag of multi-purpose compost for £12 that’s easy to work out at 12 pence per litre. So the bagged stuff is cheaper here.
I’m not saying you can’t find a cheaper supplier of bulk compost, trust me they are out there, but they are still fairly similar in price to buying large bags. And this is before you factor in any delivery charges which can be high for the big bags.