Gravel calculator
Work out how much gravel, shingle or decorative stone your job needs, in tonnes, bulk bags and 25kg bags. Enter the area and depth, pick your stone, and get the numbers in seconds.
Work out your gravel
Enter the area and the finished depth, choose your gravel, and see the tonnes, bulk bags and 25kg bags you need.
tonnes needed
Otis prices bulk bags or a loose load on the spot, day or night, straight from your live stock and delivery slots.
Uses typical densities such as 1.75 tonnes per cubic metre for gravel and shingle. Loose stone varies by type and moisture, so treat the tonnes as a close working estimate.
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Two ways to use this
Running a builders merchant?
This is exactly what Otis does live. A customer asks for gravel, Otis prices it from your own stock, checks what is in and books the delivery slot, day or night. See it running on your own catalogue.
On the tools?
Put this calculator on your own website for free. It works out the quantities for your customers and does the sums for you, and it takes two minutes to add.
How the numbers work
The calculator multiplies your area by the finished depth to get a volume in cubic metres, then multiplies that volume by the density of the stone you picked to get a weight in tonnes.
It also shows bulk bags, taken as about 850kg each, and 25kg handy bags, so you can order whichever way your merchant sells it. Whole bags are rounded up so you are never left short mid job.
This is what Otis does, instantly
A calculator works out the quantity. Otis works out the order. Ask Otis for gravel for a five by four metre area at 50mm and it checks the live price, confirms what is in stock, books a delivery slot and raises the quote, in the time it takes to read this line.
Otis is the agentic sales assistant for builders merchants. It handles trade enquiries around the clock, on the phone, by email and on your site, so the enquiries that arrive after the counter shuts still turn into orders instead of missed calls.
Gravel calculator questions
How deep should I lay gravel?
For a decorative topping over a firm base, 40mm to 50mm is typical. On a fresh dig you also need a compacted sub base beneath, usually 100mm or more, before the gravel goes down.
How many tonnes are in a bulk bag of gravel?
A standard bulk bag holds roughly 850kg, so a little under one tonne. The calculator rounds up to whole bags so you are never short on the day.
How much area does a bulk bag of gravel cover?
At a 50mm depth a bulk bag covers around 10 square metres. Go deeper and it covers less, so always work from your own length, width and depth.
Should I order a bit extra?
A small amount spare is wise for levelling, topping up low spots and settlement. Ordering the exact figure often leaves you just short once it is raked out.
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See Otis quote a load of gravel
From a few bulk bags to a full loose load with delivery, watch Otis price it and book it live from your own stock.