How much paint does your Florida house need?

How the math works

Wall area is the distance around the house times the wall height, minus the doors and windows. Gallons are that area times the number of coats, divided by how far one gallon spreads.

How far a gallon spreads comes from each paint's data sheet. Sherwin-Williams lists 250 to 300 sq ft per gallon for Emerald Exterior and Duration Exterior, and 350 to 400 for SuperPaint Exterior and A-100 Exterior, at the film thickness each sheet names.

Textured stucco is rougher and more porous than smooth siding, so the calculator uses the low end of the range for it and the high end for smooth walls. That choice is ours. No data sheet gives a percentage for stucco texture, so treat the stucco number as a sensible starting point, not a guarantee.

Coats, by the data sheets

• Repaint: Emerald and Duration call for 1 coat over a sound, previously painted surface.
• New or bare surfaces: 2 coats.
• Stucco and concrete: the SuperPaint sheet calls for a coat of Loxon masonry primer or Loxon Conditioner, then 2 coats.
• A drastic color change: a coat of primer improves how well the new color hides the old one.
• New stucco: let it cure at least 30 days first, per the Emerald sheet. See efflorescence on stucco.

What the number does not tell you

Gallons are the easy part. Whether the paint lasts depends on what happens before it goes on: washing off chalk and mildew, filling cracks, priming, and painting on a dry day. See chalking paint, stucco cracks before painting and how long paint takes to dry in Florida humidity.

Questions

Why does stucco take more paint than smooth siding?

Textured, porous stucco has more surface area and soaks up paint, so a gallon covers less of it than the label range on smooth siding. The calculator uses the low end of each product's coverage range for textured stucco. That is our assumption, not a manufacturer figure.

One coat or two?

Sherwin-Williams' Emerald and Duration data sheets call for 2 coats on new or bare surfaces and 1 coat for a repaint. For stucco, the SuperPaint sheet calls for a masonry primer plus 2 coats, and for a drastic color change it says a primer coat improves hiding.

Does this include primer?

No. Primer is a separate product with its own spread rate on its label. Bare stucco, patched areas and big color changes usually need it.

Sources

1. Sherwin-Williams, Emerald Exterior Satin, product data sheet (3/2026)
2. Sherwin-Williams, Duration Exterior Flat, product data sheet (3/2026)
3. Sherwin-Williams, SuperPaint Exterior Flat, product data sheet (9/2023)
4. Sherwin-Williams, A-100 Exterior Flat, product data sheet (8/2020)

Rather have it measured? We do free on-site estimates across Sarasota and Manatee County, with one flat written price. See exterior painting, painters in Sarasota, or the Florida Paint Guide.