15 ft Round Pool Gallons Calculator

Volume and dosing for a 15 ft round pool

A 15-foot round pool is a popular smaller above-ground size, often used for splash pools or smaller yards. At a typical 4 ft depth, it holds about 5,310 gallons -- diameter × diameter × average depth × 5.9.

Because this is a smaller volume, chemical costs are proportionally lower: reaching 3,200 ppm salt from scratch takes under 150 lbs, or about four 40 lb bags -- but note that many smaller above-ground pools use a simple chlorine floater or tablet feeder rather than a saltwater system, so check what your pool actually uses before buying salt.

Smaller pools also lose and gain chemical concentration faster relative to their size than large pools, so test more frequently if you're new to a 15 ft pool.

Where these numbers come from

The formulas and default values in this calculator are based on:

• standard round pool volume formula (diameter squared x average depth x 5.9)
• salt dosing at 1 lb per 120,000 gallons per 1 ppm change
• liquid chlorine dosing at approximately 10 fl oz of 12.5% chlorine per 10,000 gallons per 1 ppm free chlorine increase

These are planning estimates. Test your actual water, follow product labels, and check your equipment manufacturer's guidance before you buy or dose chemicals.