Swimming Pool Volume

Pool volume in liters: V = L·W·H × 1000

With a rectangular pool, the volume in cubic meters is just length × width × average depth, and multiplying that by 1,000 turns m³ into liters (V (L) = L·W·H × 1000). So an 8 × 4 × 1.5 m pool holds 48 m³, which is 48,000 L. A round pool uses V = π·r²·h instead, and for an oval pool you can approximate it with the semi-ellipse area, (π·a·b/4)·h. When dosing chlorine you're usually shooting for 1–3 ppm of free residual chlorine. The Brazilian standard ANVISA RDC 488/2021 covers pools meant for collective use, like clubs, hotels and condominiums.

Applications

Sizing a pool at home or at a club, choosing the filter pump capacity so the water turns over every 4–8 h, working out chlorine and algaecide doses, and estimating what the first fill will cost on the water bill.

FAQ

Why use average depth? Plenty of pools have a sloped floor with a shallow end and a deep end. For the volume, the arithmetic mean of the two depths does the job. If the shape gets really irregular, break it into prisms and add them up.

How much chlorine for 48,000 L? Raising free chlorine by 1 ppm takes about 48 g of active chlorine, which works out to roughly 480 mL of liquid sodium hypochlorite at 10%.

Liters or cubic meters on the water bill? Utilities in Brazil bill in m³, where 1 m³ = 1,000 L. Filling a 48 m³ pool burns through roughly half a month's water for a family of four.