Pool Size Reference
Seven common pool sizes, computed through the same volume, chlorine, alkalinity, and pump calculators used throughout this site — a quick side-by-side comparison, not a substitute for measuring and dosing your own pool.
Before adding any chemical:
Add chemicals to water, one at a time — never to each other, and never into the same bucket or scoop. Combining different chlorine types, or combining chlorine with an acid, can produce dangerous gas. Give each addition time to circulate and re-test before adding more; never chase a reading by dosing repeatedly in a short window. The amounts below are planning estimates from a fixed illustrative scenario (see the FAQ), not a measurement of your specific pool or water.
Volume, chlorine, alkalinity, and pump time by pool size
| Pool size | Gallons | Chlorine dose (2→5 ppm FC) | Alkalinity dose (70→90 ppm TA) | Pump run time (1 turnover @ 60 GPM) |
|---|---|---|---|---|
| Small rectangular (12 × 24 ft, 4.5 ft avg depth) | 9,720 gal | 29.86 fl oz | 2.92 lb | 2.70 hr |
| Medium rectangular (16 × 32 ft, 5 ft avg depth) | 19,200 gal | 58.98 fl oz | 5.76 lb | 5.33 hr |
| Large rectangular (20 × 40 ft, 5.5 ft avg depth) | 33,000 gal | 101.38 fl oz | 9.9 lb | 9.17 hr |
| Small round (18 ft diameter, 4 ft avg depth) | 7,646 gal | 23.49 fl oz | 2.29 lb | 2.12 hr |
| Medium round (24 ft diameter, 4.5 ft avg depth) | 15,293 gal | 46.98 fl oz | 4.59 lb | 4.25 hr |
| Medium oval (15 × 30 ft, 4.5 ft avg depth) | 13,568 gal | 41.68 fl oz | 4.07 lb | 3.77 hr |
| Large oval (18 × 36 ft, 5 ft avg depth) | 21,708 gal | 66.69 fl oz | 6.51 lb | 6.03 hr |
Every figure above comes from the same poolVolume(), chlorineDosing(), phAlkalinity(), and pumpRuntime()functions behind the individual calculators on this site — there is no separate, hand-typed table behind this page.
How to read this table
Each row starts from a preset pool shape and dimensions, runs them through the Pool Volume Calculator’s logic to get gallons, then feeds that gallon figure into the same fixed scenario for every row: a chlorine dose raising free chlorine from 2 ppm to 5 ppm with 12.5% liquid chlorine, an alkalinity dose raising total alkalinity from 70 ppm to 90 ppm with baking soda, and a pump run time for one full turnover at a representative 60 GPM flow rate.
Holding the scenario fixed and only changing pool size is what makes the rows comparable to each other: the difference between the small and large rectangular presets, for instance, is entirely down to volume, not a different dosing target. Your own pool almost certainly has different current and target readings than the fixed scenario used here — use the individual calculators linked throughout this page with your own numbers once you know your actual volume and test results.
Notice that the medium oval preset holds less water than the medium rectangular preset despite having a similar footprint, and the round presets hold less again for their outer diameter — that's not a rounding quirk, it's the same shape-driven difference covered in Why Pool Shape Changes Your Gallon Count More Than You’d Expect.
Frequently Asked Questions
Why do the chlorine and alkalinity columns use fixed numbers instead of my pool's actual readings?
This table exists to compare pool sizes side by side, so every row is run against the same illustrative scenario: free chlorine raised from 2 ppm to 5 ppm, and total alkalinity raised from 70 ppm to 90 ppm. Your own pool's actual current and target readings will give a different amount — use the Chlorine Dosing Calculator and the pH & Alkalinity Balance Calculator directly with your own numbers for a dose sized to your situation.
Why does the pump run-time column assume 60 GPM?
60 GPM is a representative residential pump flow rate used here so every pool size can be compared on the same basis. Real flow rate varies by pump model, plumbing, and how clean the filter is — swap in your own pump's actual GPM on the Pump Run-Time Calculator for an accurate schedule.
Why does the oval preset hold less water than a rectangle with the same length and width?
The oval formula uses a lower multiplier (6.7) than the rectangular formula (7.5) because real oval above-ground pools are closer to a rectangle with rounded ends than to a full rectangle, so the same footprint holds less water. A full worked comparison across shapes is in Why Pool Shape Changes Your Gallon Count More Than You'd Expect, linked below.
Is this a substitute for measuring my own pool?
No. These are seven illustrative preset sizes for comparison, not a lookup table to match your pool against. Measure your own length, width or diameter, and average depth, and run them through the Pool Volume Calculator for an accurate gallon count before dosing anything.
Dosing guidance only, not a substitute for the manufacturer’s instructions or a professional water test. Pool chemicals can be hazardous — read and follow the product label, add chemicals to water (never water to chemical), never mix different products together, and keep them out of reach of children and pets.
Use it with
- Pool Volume Calculator— measure and calculate your own pool’s actual gallons rather than reading off the nearest preset.
- Chlorine Dosing Calculator— dose from your pool’s real current and target free chlorine readings.
- pH & Alkalinity Balance Calculator— dose soda ash, muriatic acid, or baking soda from your own readings.
- Pump Run-Time Calculator— use your pump’s actual flow rate instead of the 60 GPM reference figure.