Rex says
Everyday utility math — the kind you'd otherwise pull up four browser tabs for. I keep it to one clean answer.
Try a scenario
Click to load — tweak from there.Inputs
Result
Total pool gallons
15,745
Surface area
467
sq ft
Total cubic feet
2,099
Psst — share this and help Rex grow
One click, a permanent link with your numbers baked in.
How to use this
- 1Enter length (ft).
- 2Enter width (ft).
- 3Enter water depth (ft).
- 4Read your total pool gallons on the right — it updates as you type.
- 5Hit Share to keep the scenario or send it to someone.
About this calculator
Oval above-ground pools use an ellipse footprint rather than a true circle, so their gallon calculation swaps in the ellipse area formula — pi times the semi-major axis times the semi-minor axis — in place of the circle formula used for round pools. This calculator takes the pool's overall length and width (the full diameter measurements, not the radii) along with water depth, computes the elliptical surface area, and multiplies by depth and 7.5 gallons per cubic foot to return total gallons. Oval pools are popular for yards that are long and narrow rather than square, letting more swimming length fit a tighter footprint than a round pool of similar surface area would, but their capacity is easy to misjudge without doing the actual ellipse math since the shape reads visually similar to a much smaller circle. As with any above-ground pool, getting an accurate gallon figure matters for dosing shock, chlorine, and algaecide correctly relative to labeled per-10,000-gallon instructions.
Worked example
Using the values the calculator loads with:
Inputs
- Length: 33 ft
- Width: 18 ft
- Water depth: 4.5 ft
Results
- Total pool gallons: 15,745
- Surface area: 467
- Total cubic feet: 2,099
What each field means
Inputs
- Length (ft)
- The length used in the calculation, measured in ft. Starts at 33 ft so you have a working example on load. Accepted range: 5–60 ft.
- Width (ft)
- The width used in the calculation, measured in ft. Starts at 18 ft so you have a working example on load. Accepted range: 5–40 ft.
- Water depth (ft)
- The water depth used in the calculation, measured in ft. Starts at 4.5 ft so you have a working example on load. Accepted range: 1–12 ft.
Results
- Total pool gallons
- Returned as a whole number and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Surface area
- sq ft
- Total cubic feet
- Returned as a whole number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
How is an oval pool's area different from a round pool's?
A round pool uses one radius squared in its area formula, while an oval pool uses two different radii — half the length and half the width — multiplied together, since an ellipse isn't equally wide in every direction.
How much water does a typical 33x18 oval pool hold?
At a 4.5 ft depth, a 33x18 oval pool holds roughly 15,700 gallons, comparable to a similarly-sized round pool despite looking narrower along its width.
Should I measure the liner or the frame for length and width?
Measure the actual water surface dimensions once filled, not the outer frame or deck footprint, since frame and decking add extra width that isn't part of the water volume.
Does this formula work for kidney-shaped pools too?
No, kidney-shaped pools have an irregular curved footprint that the ellipse formula doesn't accurately capture — use a dedicated kidney pool calculator that accounts for the two-radius curved shape instead.
Accuracy and limitations
- Estimates assume standard, average conditions — local rules, pricing, and materials vary.
- Results are rounded for readability; add a buffer before ordering, booking, or committing.
- Double-check anything with a real cost attached against a local quote.
Related tools
Round Pool Gallons Calculator
Get total gallons for a round or circular above-ground pool from diameter and depth.
Rectangular Pool Gallons Calculator
Convert a rectangular pool's dimensions into total gallons for chemical dosing.
Kidney Pool Gallons Calculator
Estimate total gallons for a curved kidney-shaped in-ground pool.
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Oval Pool Gallons Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/pool-gallons-oval-calculator
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/pool-gallons-oval-calculator" target="_blank" rel="noopener">Oval Pool Gallons Calculator — RevenueLab</a> (2026).</p>
Source: [Oval Pool Gallons Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/pool-gallons-oval-calculator) (2026).