Pool Plaster and Resurfacing Material Calculator
Bags of plaster, quartz or pebble finish — or gallons of pool paint — from your pool's interior surface area, using each maker's published coverage rate. No login.
How this is calculated
Resurfacing quantity is one chain: interior area, times the number of coats, plus your waste allowance, divided by the coverage rate the manufacturer publishes — then rounded up, because nobody sells three-quarters of a bag. Because makers publish coverage as a band (a rough shell drinks more material than a smooth one), the answer comes back as a band too.
interior area (rect) = (L × W) + (L × avg depth × 2) + (W × shallow) + (W × deep)
avg depth = (shallow + deep) / 2
covered area = interior area × coats
order area = covered area × (1 + waste%)
units (most) = ceil( order area / tight coverage rate )
units (least) = ceil( order area / generous coverage rate )
order weight = units × published bag weightCoverage defaults are quoted from the makers' own sheets: SGM publishes 22–25 sq ft per 80 lb bag at a 3/8″–1/2″ finished thickness for Pool Brite plaster and Diamond Brite quartz, and 18–22 sq ft per 80 lb bag for River Rok pebble, noting in both cases that surface roughness affects coverage. Kelley Technical Coatings publishes 125–150 sq ft per gallon for one-coat Zeron epoxy, 225–250 for the two-coat Poxolon 2 system, 250–275 for Paralon 2 chlorinated rubber, and 250–300 for water-based Hydrolon. Paint figures are per coat, so a two-coat system needs roughly twice the gallons — which is why two coats of Poxolon 2 and one coat of Zeron land within a gallon or two of each other on the same pool.
The waste allowance is the one number here that is not published by anyone: it is your judgment about spillage, cuts, and how uneven the old shell is. Nothing is stored, and no measurement leaves your browser.
How much material does a pool resurface take?
Order from the pool’s interior (wetted) surface area — floor plus all four walls. A 16 × 32 ft pool with a 3 ft shallow and 8 ft deep end is about 1,040 sq ft (96.6 m²) of shell. At SGM’s published 22–25 sq ft per 80 lb bag, that is 46–52 bags of white plaster or quartz finish with a 10% waste allowance; pebble at 18–22 sq ft per bag takes 52–64.
Interior area is the number everything else hangs off
The top water surface and the interior surface are two different measurements,
and resurfacing uses the larger one. PoolTile.ca publishes the rectangular
decomposition the calculator uses: (L × W) + (L × avg depth × 2) + (W × shallow depth) + (W × deep depth). On the 16 × 32 ft example above, the floor
is 512 sq ft and the four walls add another 528 — so a quantity worked from the
water surface would be half of what the job needs.
For round, oval and kidney shells there is no published wall-wrap formula worth trusting, so measure the curved walls in sections and bring the total in. The pool surface area calculator returns the wetted figure for rectangles and the perimeter and waterline-tile band for every shape, which is the other order you place on a renovation.
Bags by pool size — plaster, quartz and pebble
Every row is the full interior area with a 10% waste allowance, rounded up to whole 80 lb bags at the makers’ published rates.
| Pool (W × L, shallow–deep) | Interior area | Plaster or quartz (22–25 sq ft/bag) | Pebble (18–22 sq ft/bag) |
|---|---|---|---|
| 10 × 20 ft, 3–5 ft | 440 sq ft / 40.9 m² | 20–22 bags | 22–27 bags |
| 12 × 24 ft, 3–6 ft | 612 sq ft / 56.9 m² | 27–31 bags | 31–38 bags |
| 14 × 28 ft, 3–8 ft | 854 sq ft / 79.3 m² | 38–43 bags | 43–53 bags |
| 16 × 32 ft, 3–8 ft | 1,040 sq ft / 96.6 m² | 46–52 bags | 52–64 bags |
| 18 × 36 ft, 3–8 ft | 1,242 sq ft / 115.4 m² | 55–63 bags | 63–76 bags |
| 20 × 40 ft, 3–8 ft | 1,460 sq ft / 135.6 m² | 65–73 bags | 73–90 bags |
At 80 lb a bag, the 16 × 32 ft pool is between 3,680 and 4,160 lb of finish material, and the 20 × 40 ft in pebble runs 5,840–7,200 lb — close to three and a half tons at the top of the band. That is a delivery and staging question, not just a purchase-order line, which is why the calculator prints order weight alongside the bag count.
Gallons by pool size — pool paints
Paint coverage is published per gallon per coat, so the coat count is half the answer. These rows carry the same 10% waste allowance.
| Interior area | Zeron epoxy, 1 coat (125–150 sq ft/gal) | Poxolon 2 epoxy, 2 coats (225–250 sq ft/gal) | Paralon 2 rubber, 2 coats (250–275 sq ft/gal) |
|---|---|---|---|
| 440 sq ft | 4 gal | 4–5 gal | 4 gal |
| 612 sq ft | 5–6 gal | 6 gal | 5–6 gal |
| 854 sq ft | 7–8 gal | 8–9 gal | 7–8 gal |
| 1,040 sq ft | 8–10 gal | 10–11 gal | 9–10 gal |
| 1,242 sq ft | 10–11 gal | 11–13 gal | 10–11 gal |
| 1,460 sq ft | 11–13 gal | 13–15 gal | 12–13 gal |
Kelley Technical Coatings also publishes 250–300 sq ft per gallon for Hydrolon, its water-based acrylic, but states no coat count on that product page — so the calculator leaves the coats field for you to set from the can rather than guessing on your behalf. Note how close the one-coat and two-coat epoxies land: Zeron covers less per gallon but only goes on once, so the two systems differ by a gallon or two on the same shell.
Why the answer is a band and not a single number
Both makers publish a range, and SGM says why on its own sheets — surface roughness affects coverage rates. A shell that has just been chipped out drinks material at the tight end of the band; a smooth, well-prepared one lands at the generous end. The waste allowance is the one figure in the tool that no manufacturer publishes: it is your judgment about spillage, an uneven shell, and how far the supply house is. The default is 10% and it is fully editable.
What this does not price
Material quantity is not a job cost. Chip-out, bond coat, tile, plumbing, start-up water and labor all sit outside it. A drain-and-acid-wash is a cleaning, not a resurface — if the plaster is stained rather than failed, price it with the acid wash cost calculator before quoting a full interior. Document what you actually found on the shell with the pool inspection condition form, and size the refill with the pool volume calculator — a resurface ends with a full pool, and that water is a real line on the invoice.
Interior work happens in the off-season on both sides of the equator: roughly October–March in the northern hemisphere and April–September in Australia, New Zealand and southern Africa. The quantities are identical; only the calendar moves.
Frequently asked questions
How many bags of Diamond Brite do I need for a pool?
How much plaster does it take to replaster a pool?
How much paint do I need to paint a pool?
Does a pebble finish use more material than quartz?
Do I use the water surface area or the wetted area for resurfacing?
Sources
- Pool Brite pre-blended pool plaster — information sheet (coverage: 22–25 sq ft per 80 lb bag at 3/8"–1/2"). SGM, Inc.. Retrieved .
- Diamond Brite exposed-aggregate pool finish — information sheet (coverage: 22–25 sq ft per 80 lb bag at 3/8"–1/2"). SGM, Inc.. Retrieved .
- River Rok natural pebble pool finish — information sheet (coverage: 18–22 sq ft per 80 lb bag at 3/8"–1/2"). SGM, Inc.. Retrieved .
- Olympic Zeron one-coat epoxy pool paint — 125–150 sq ft per gallon. Kelley Technical Coatings. Retrieved .
- Olympic Poxolon 2 two-coat epoxy pool paint — 225–250 sq ft per gallon. Kelley Technical Coatings. Retrieved .
- Olympic Paralon 2 chlorinated-rubber pool paint — 250–275 sq ft average per gallon, two coats. Kelley Technical Coatings. Retrieved .
- Olympic Hydrolon water-based acrylic pool paint — 250–300 sq ft average per gallon. Kelley Technical Coatings. Retrieved .
- How to measure and calculate your pool size — rectangular interior-area formula. PoolTile.ca. Retrieved .