Which number to use
The order sheet shows several quantities. They mean different things:
| Line | Use it for |
|---|---|
| Calculated volume | Checking your measurements — it's pure geometry. |
| Purchase volume | The exact amount needed including your allowances. |
| Estimated weight | Quoting suppliers who sell by the ton — only as good as the density. |
| Bulk order | The figure to ask for: rounded up to the next ½ yd³ or ½ ton. |
| Bags | Store-bought bagged material: a whole-bag count for the bag size you entered. |
What to tell the supplier
- Pick the material and sizeName and size number (e.g. #57 crushed stone, pea gravel). Ask what the supplier stocks.
- Bring your quantity — with its unitFrom the order sheet: the rounded bulk order in yd³ or m³, or tons/tonnes if they sell by weight.
- Give the dimensions and depthArea, depth and whether the depth is loose or compacted, so they can sanity-check your number.
- Ask for their conversion factorIf they sell by weight, ask their tons per yard (or density) and enter it in the calculator.
- Confirm units and incrementsUS ton or metric tonne? Minimum load? Half-yard steps? Bag size?
- Ask about delivery and accessWhere the load can be tipped, and any delivery charge — these aren't in our cost line.
The Print order sheet and Copy result buttons on every calculator produce this information in one block, including your measurements and the link to reopen the calculation.
Volume or weight?
Suppliers sell bulk aggregate by volume (cubic yards or cubic metres) or by weight (tons or tonnes). If they sell by weight, the conversion depends on their stone. Ask for their tons-per-yard figure or density and enter it — don't rely on a general value. A metric tonne (1,000 kg) is about 10% heavier than a US ton (2,000 lb); confirm which they mean.
Bags or bulk?
For the 12 × 12 ft pea gravel patio in our worked examples, the purchase volume is 1.47 yd³: either 80 bags of 0.5 ft³ or a 1.5 yd³ bulk delivery. Which is cheaper depends on local bag prices, the bulk price, and the delivery charge — enter your own prices in the calculator to compare. Bags also cost handling time; bulk needs somewhere to tip the load.
Rounding and minimums
GravelMatter rounds bulk orders up to the next half unit because that's a common delivery step, but your supplier's increments and minimum load may differ. If you're just over a step, consider whether the waste allowance already covers it, or whether a slightly different depth makes sense.
Before delivery
- Agree where the load can be tipped, and protect lawns or paving if needed.
- Check access width and overhead clearance for the truck.
- Have tools ready to spread the load the same day if it's on a driveway or road edge.
Delivery charges, minimum orders and access fees are outside the calculators' cost line — ask for them explicitly.
Ordering mistakes
Treating tons and cubic yards as the same thing
What goes wrong: Weight depends on the material. The same 2 yd³ is about 2.62 tons of dry sand but 3.38 tons of wet gravel at the reference values.
How to avoid it: Convert with a density you can see — ideally your supplier's — using the yards-to-tons calculator.
Assuming every gravel weighs the same
What goes wrong: The published gravel range of 91–120 lb/ft³ turns 2 yd³ into anything from 2.46 to 3.24 tons.
How to avoid it: Ask the supplier for their weight per yard or conversion factor and type it into Density.
Ordering the exact decimal
What goes wrong: 1.47 yd³ isn't something most suppliers deliver; bags come in whole units.
How to avoid it: Use the rounded bulk-order line (next ½ unit) or the whole-bag count, and confirm the supplier's increments.