Calculator 06 / 08
Pea gravel calculator
Pea gravel is often bought in bags for small jobs and in bulk for larger ones. This shows both, so you can see where bulk starts to make sense.
- Outputs
- yd³ · tons · tonnes · bags · cost
- Material basis
- Pea gravel · 105 lb/ft³ default, editable
- Method
- Formulas & sources
Bags or bulk?
Pea gravel is small, rounded stone. Because it rolls rather than locks, it is mostly used where it won't carry heavy loads: patios, paths, play areas, and around pavers. Small jobs are often bought in bags and larger ones delivered loose. The result shows both so you can compare:
| Purchase volume | 0.5 ft³ bags | 50 lb bags at 105 lb/ft³ |
|---|---|---|
| 0.25 yd³ (6.75 ft³) | 14 | 15 |
| 0.5 yd³ (13.5 ft³) | 27 | 29 |
| 1 yd³ (27 ft³) | 54 | 57 |
| 2 yd³ (54 ft³) | 108 | 114 |
Bag counts are rounded up to whole bags. Check the bag label — bag sizes vary by brand.
Worked example: small patio
| Patio | 12 ft × 12 ft = 144 ft², 3 in deep |
|---|---|
| Volume | 36 ft³ = 1.33 yd³ |
| + Waste 10% | 39.6 ft³ = 1.47 yd³ |
| Weight | ≈ 2.08 US tons at 105 lb/ft³ |
| Bags | 80 × 0.5 ft³ |
About the density
We did not find a reliable published density specific to pea gravel, so this tool uses the general dry-gravel value, 105 lb/ft³ source, and shows the wider gravel range source. Rounded stone of one size leaves more air between pieces than well-graded crushed stone, so treat the tons figure as approximate and use your supplier's number. For what pea gravel is and isn't good for, see types and sizes.
Reading the result
Each line of the order sheet answers a different question. Read them in order: geometry first, then your allowances, then the quantity you can actually buy.
- Calculated volume
- Area × depth — pure geometry, before any allowance.
- + Compaction
- Extra loose material if the depth is a compacted depth. Shown only when set.
- + Waste
- Your margin for spillage, edges and uneven ground, applied after compaction.
- Purchase volume
- What to buy: volume × (1 + compaction) × (1 + waste). The exact figure.
- Estimated weight
- Purchase volume × the density shown. Only as accurate as that density.
- Bulk order
- Purchase volume and weight rounded up to the next ½ yd³ / ½ ton (½ m³ / ½ t in metric).
- Bags / cost
- Whole bags of the size you entered; cost = your price × the matching quantity.
What this calculator assumes
- Dimensions are the plan area that will actually be covered.
- Depth is an average across the area.
- Areas are flat; slopes aren't adjusted for.
- Density is a loose bulk density — a general published value unless you replace it.
- Waste and compaction are multiplied, not added.
- Bags are rounded up to whole bags; bulk orders up to the next ½ unit.
- No reliable pea-gravel-specific figure was found, so the general dry-gravel value is used. Ask your supplier for theirs.
It can't see your site or your supplier's stone. What the calculators cannot know · Full methodology
Common mistakes with this calculator
Buying bags without checking the size
What goes wrong: Bag sizes vary by brand; 0.5 ft³ and 50 lb bags hold different amounts.
How to avoid it: Enter the size printed on the bag — by volume or by weight.
Depth entered in the wrong unit
What goes wrong: Typing 3 for a 3-inch layer while the depth unit is set to feet multiplies the volume by 12: a 10 × 10 ft area becomes 11.11 yd³ instead of 0.93 yd³.
How to avoid it: Check the unit beside the depth field. The calculators warn when a depth is over 24 in.
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.
Questions
How many bags of pea gravel do I need?
Divide the purchase volume in cubic feet by the bag size. A 0.5 ft³ bag is 1/54 of a cubic yard, so one cubic yard is 54 bags. The calculator rounds up to whole bags.
How much area does a cubic yard of pea gravel cover?
At 2 in deep, one cubic yard covers 162 ft²; at 3 in, 108 ft²; at 4 in, 81 ft².
Is pea gravel good for a driveway?
It's used on some driveways, but rounded stone moves under tyres more than crushed angular stone does. See the driveway guide for how driveways are usually layered.