Catch Basin Gravel Calculator
Estimate compacted gravel for catch-basin bases and side backfill using excavation dimensions, basin dimensions, base depth, quantity, compaction allowance and bag size.
Default project preview
63 bags
Net gravel volume
1.01 yd³
Base gravel each
0.077 yd³
Side backfill each
0.26 yd³
Purchased bag volume
1.17 yd³
Calculator
Build the material order
Your order will appear here
Enter the project details and calculate a rounded material estimate.
Input and output guide
What each value means
The labels and units below are part of this calculator’s visible methodology. Replace every default with measurements or product data from the actual project.
Excavation length
Enter this project assumption in ft. The current imperial default is 2.5 ft.
Excavation width
Enter this project assumption in ft. The current imperial default is 2.5 ft.
Catch-basin outside length
Enter this project assumption in ft. The current imperial default is 1.25 ft.
Catch-basin outside width
Enter this project assumption in ft. The current imperial default is 1.25 ft.
Gravel side-backfill height
Enter this project assumption in ft. The current imperial default is 1.5 ft.
Gravel base depth
Enter this project assumption in in. The current imperial default is 4 in.
Number of equal basins
Enter this project assumption in a unitless value. The current imperial default is 3. Minimum: 1.
Compaction and handling allowance
Enter this project assumption in %. The current imperial default is 15 %. Minimum: 0. Maximum: 50.
Gravel volume per bag
Enter this project assumption in ft³. The current imperial default is 0.5 ft³.
Price per bag
Enter this project assumption in a unitless value. The current imperial default is 7. Minimum: 0.
How to read the outputs
Net gravel volume
3 equal basins. Default preview: 1.01 yd³.
Base gravel each
full excavation footprint. Default preview: 0.077 yd³.
Side backfill each
excavation minus basin footprint. Default preview: 0.26 yd³.
Purchased bag volume
full bags. Default preview: 1.17 yd³.
Base depth
editable installation assumption. Default preview: 4 in.
Bagged gravel cost
full bags only. Default preview: $441.00.
Methodology
Transparent calculation
BuildMeter converts every input to a consistent internal unit, applies the selected allowance, and rounds products up to whole purchasable units.
Gravel volume = full excavation base volume + side-backfill volume outside the basin. Multiply by basin count, add compaction allowance and round to full bags.
Related tools
Continue planning the project
BuildMeter Guides
Understand the measurements and assumptions
Use these visible reference guides before changing project inputs or planning allowances.
FAQ
Catch Basin Gravel Calculator questions
Why subtract the basin footprint from side backfill?+
The basin occupies the center of the excavation, so only the surrounding annular space receives side gravel.
Is gravel always used around the full basin height?+
No. Backfill material and height depend on the product, surface loading and installation detail.
Does this size the catch basin or outlet pipe?+
No. Runoff, grate capacity, debris and pipe hydraulics determine basin and outlet sizing.