To estimate how much dirt to fill a pool, calculate the pool cavity in cubic feet and divide by 27 to get cubic yards. For a simple rectangular pool, multiply length by width by average depth, then divide by 27. That gives a useful geometric starting point—not an order quantity. The contractor still needs to account for the pool's real shape, shell and deck demolition, material that remains or leaves, finish grade, compacted density, and the approved source of fill.
A rough homeowner calculation can help compare proposals and spot missing scope, but it should not replace a site survey or earthwork plan. In Bakersfield and Kern County, the responsible contractor and permitting authority must confirm the removal method, acceptable material, placement, compaction, inspections, and documentation for the address and intended use of the finished area.
Estimate how much dirt to fill a pool with a rough formula
Use feet for every measurement:
Length × width × average depth ÷ 27 = approximate cubic yards
A cubic yard contains 27 cubic feet. The U.S. Department of Agriculture's earthwork quantity-computation guidance uses that same conversion when turning measured cubic feet into cubic yards. NIST also lists the official approximate conversion from cubic yards to cubic meters for proposals that use metric quantities.
Average depth is commonly approximated as shallow-end depth plus deep-end depth, divided by two. That shortcut is most useful when the floor changes at a fairly steady rate. A pool with a long shallow shelf, compact deep well, diving bowl, raised spa, broad steps, or sharply changing slopes needs separate measurements. The more irregular the cavity, the less reliable one average depth becomes.
Work through a sample pool volume
Consider a hypothetical rectangular pool that is 30 feet long and 15 feet wide, with a 3.5-foot shallow end and an 8-foot deep end. Its rough average depth is 5.75 feet:
- Average depth: (3.5 + 8) ÷ 2 = 5.75 feet
- Cavity volume: 30 × 15 × 5.75 = 2,587.5 cubic feet
- Geometric volume: 2,587.5 ÷ 27 = about 95.8 cubic yards
That result does not mean the project should order 96 cubic yards. It represents an idealized space bounded by the entered dimensions. It does not yet reflect curves, steps, benches, the thickness and disposition of the shell, the removed pool deck, compacted-versus-loose volume, or a different surface zone for topsoil or patio base. It is a conversation starter for an estimate, not a delivery instruction.
For kidney-shaped or free-form pools
Divide the plan view into smaller rectangles and rounded sections, estimate each portion, and add the results. Where depth changes unevenly, divide the length into shallow, transition, and deep sections instead of using one average for the entire pool. A contractor can check the estimate with site measurements, elevations, or cross-sections. USDA guidance notes that irregular earthwork areas require special treatment at their edges; the same caution applies to a curved backyard pool.
Why the delivered dirt quantity differs from pool volume
Soil does not occupy one fixed volume through excavation, trucking, placement, and compaction. Federal Highway Administration guidance says shrink and swell factors adjust earthwork quantities between their original and compacted states, and recommends using the project geotechnical information rather than a universal factor. Review the agency's 2024 earthwork representation guide for the distinction between bank and compacted cubic yards.
Several project decisions can move the actual quantity above or below the rough cavity calculation:
- Removal method: full pool removal takes out the entire shell, while a partial removal or fill-in may leave approved portions in place.
- Existing material: suitable excavated soil may be reusable; organic, contaminated, oversized, or otherwise unsuitable material may need separate handling.
- Demolition limits: removing coping, decks, footings, a spa, or an equipment pad changes both void and debris quantities.
- Final surface: lawn, planting soil, aggregate, pavement base, and future foundations can require different upper layers and finished elevations.
- Settlement control: fill is placed and compacted in lifts, so delivered loose volume cannot simply be equated with finished compacted volume.
- Site geometry: steps, slopes, wall thickness, over-excavation, trenches, and access-path repairs may not appear in basic pool dimensions.
Do not add a generic percentage for every pool. Ask the bidder to show the measured cavity volume, identify which adjustment factors apply to the proposed material, and state whether quoted quantities are loose, delivered, bank, or compacted cubic yards.
Separate fill quantity from fill quality and compaction
A correct yardage does not make unsuitable material acceptable. “Dirt” can describe soils with very different gradation, plasticity, organic content, moisture response, and support characteristics. The approved material must match the project, especially when the former pool will carry hardscape or a future structure.
Kern County Public Works maintains a current grading resources page with its grading code and inspection forms. Those resources are relevant starting points for an unincorporated Kern County parcel, not a universal specification for every pool. A property inside Bakersfield or another incorporated city may be reviewed by a different authority, and an approved plan or soils report can impose project-specific criteria.
Use the site's detailed guide to pool removal backfill and compaction to compare material approval, lifts, moisture conditioning, density testing, and records. The quantity calculation and compaction plan belong together: one estimates how much material is needed, while the other defines how it becomes stable fill.
Ask for a fill schedule, not just a truck count
“Ten truckloads” is not a comparable unit unless the proposal states the truck capacity, loading method, material, measurement basis, and treatment of partial loads. Traffic limits, access, staging space, and the available equipment can also affect delivery size without changing the compacted quantity the pool needs. The limited-access pool removal checklist helps map that route before deliveries begin.
Ask every bidder to answer the same quantity questions:
- What pool dimensions, elevations, or cross-sections support the estimate?
- Does the volume assume full removal or partial fill-in, and which shell or deck material remains?
- How many compacted cubic yards are needed, and how is that converted to delivered loose material?
- What type and source of fill is proposed, and who approves it before placement?
- Are delivery, testing, water, overages, rejected loads, and unused material included?
- What final elevation and surface layer are included?
- Which tickets, density reports, inspection records, and photographs will the owner receive?
Compare these answers with demolition, hauling, permits, and restoration on the Bakersfield pool removal cost guide. A low allowance can produce a change order if the measured cavity or compaction response requires more approved material; an unexplained high allowance can be equally difficult to evaluate.
Measure first, then price the complete earthwork scope
Start with length, width, and representative depths, convert cubic feet to cubic yards, and label the answer as a rough geometric volume. Then have the contractor reconcile that number with the actual demolition limits, approved fill, shrink or swell adjustment, compaction plan, final grade, and intended use. That sequence turns “how much dirt?” into a bid item you can understand and compare.
When you are ready, request a project-specific pool removal estimate. Include pool dimensions, shallow and deep depths, shell type, deck scope, access photos, removal preference, and plans for the finished area so responding professionals can explain their quantity assumptions rather than guessing from a single measurement.