Pool Paint Calculator

Why This One Is Different

You've drained the pool and you're standing over chalky, pitted gunite, trying to work out how many gallons to grab before the store closes. Pool paint coverage sits well below wall paint's range for a simple reason: gunite, plaster, and other masonry pool surfaces are porous, and porous substrates drink coating instead of holding a film on top the way primed drywall does. The manufacturer product-data-sheet class for pool and masonry coatings runs roughly 150-300 sq ft per gallon (about half of interior wall paint's 250-400 sf/gal band), and a rough, pitted, or unsealed surface puts you at the low end of that range, not the average. This calculator sizes gallons off your pool's surface area at that band, but the honest caveat is that draining, acid-washing, and patching typically cost you more time and money than the paint itself; buy coating last, after prep is scoped.

Where the Numbers Come From

• Pool and masonry coating coverage runs roughly 150-300 sq ft per gallon, about half the 250-400 sf/gal range for interior wall paint, because porous masonry substrates absorb more material per coat. Source: pool-paint PDS class (coverage.ts engine convention)
• Rough, porous, or previously chalking masonry pushes actual consumption toward the low end of the 150-300 sf/gal band rather than the midpoint: texture, not gallon count, is what should set your expectation. Source: coverage.ts engine convention
• Openings are not deducted from the measured area by default (P10-style pro measurement convention), and two coats is the default coat count for film-forming coatings. Source: coverage.ts engine convention (PCA/PDCA P10 measurement standard, via construction-estimating canon)
• Worked example: an 800 sq ft pool shell at 2 coats and the low end of the band (150 sf/gal) needs 1,600÷150 = 10.7, rounding up to 11 gallons; at the high end (300 sf/gal) it needs 6 gallons, nearly double, from surface texture alone. Source: worked example, coverage.ts formula