Pool Calculator
Measure the pool once for its surface areas, perimeter and water volume — then shell concrete from the thicknesses on your plans, finish bags from the manufacturer's coverage, and coping from the perimeter.
MaterialQuant calculates material quantities from the dimensions and shell thicknesses you enter. Shell thickness, reinforcement, concrete strength and every other structural requirement must come from your pool's plans, its engineer and the code that applies where you build. A quantity here says nothing about whether a design is adequate.
Measure it once
Patios and pool decks, wall runs and pools. Every module below reads these.
Rectangular pool. Leave the deep end blank for a constant depth.
Blank for a constant depth. Different depths assume one even slope — an estimate.
What are you building?
Pick one or several. Each reads the measurements above.
Pool
Quantities from your design — not a design. MaterialQuant calculates material quantities from the dimensions and shell thicknesses you enter. Shell thickness, reinforcement, concrete strength and every other structural requirement must come from your pool's plans, its engineer and the code that applies where you build. A quantity here says nothing about whether a design is adequate.
Shell concrete
Enter the thicknesses specified by your pool plans or engineer. There is no default — shell thickness is a structural design decision.
Shotcrete loses material to rebound — generally more with dry-mix gunite than wet-mix. There is no default: enter the rebound and placement allowance your contractor uses.
Interior finish
Manufacturer: "Each 80 lbs. bag will cover approximately 22—25 sq. ft., to a thickness of minimum 3/8″—½″." "Surface roughness affects coverage rates."
Coping
Round and oval pools need curved (radius) coping or cut pieces along the curves. Enter the length each piece covers along the pool edge, as your supplier quotes it. Pool decking around it is an area — use Pavers.
One measurement, three quantities
A pool's shape and depths give its floor area, wall area and perimeter. Shell concrete needs the floor and wall areas separately (they can be different thicknesses), the interior finish needs their sum, and coping needs the perimeter. Enter the pool once and all three follow — change the length and all three move together.
Pool shapes
| Shape | How it is calculated |
|---|---|
| Rectangle | Rectangle. With equal shallow and deep depths it is exact. With different depths it assumes ONE even slope from the shallow wall to the deep wall — an estimate, labelled as one. |
| Round | Round, constant depth. Exact. |
| Oval | Rounded-end oval — straight sides with semicircular ends. Constant depth. Exact for that shape. |
| Custom | Enter floor area, wall area and perimeter from your plans or takeoff. For freeform and kidney pools this is more accurate than approximating the shape. |
Most pools have a flat shallow area, a transition slope and a deeper hopper. A single even slope between the end walls will not match that exactly. For a pool with a hopper, take the floor and wall areas from the plans and use Custom.
Pool concrete and gunite
The shell is calculated as surface area times the thickness you enter, for the floor and the walls separately. It is not a ready-mix pour: a pool shell is sprayed by a shotcrete or gunite crew, so the Concrete Calculator's truckload, short-load and bag logic is deliberately not applied. You get the calculated in-place volume, and the order volume after the allowance your contractor sets.
No default thickness. The American Shotcrete Association states that pool wall thickness is part of the pool engineer's design. There is no universal thickness, and offering one would put a structural assumption into a quantity tool. Until thicknesses are entered, the shell volume is not calculated.
Pool plaster and quartz finish
| Finish | Coverage per bag | Package |
|---|---|---|
| SGM Pool Brite (plaster) Applied at minimum ⅜ in. to ½ in. | 22–25 ft² | 80 lb bag |
| SGM Diamond Brite (quartz) Applied at minimum ⅜ in. to ½ in. | 22–25 ft² | 80 lb bag |
SGM states that surface roughness reduces coverage, and a pool finish is applied in one continuous session — running out part-way is far more costly than a spare bag. Bags always round up.
Pebble and other finish systems publish coverage per product and are often applied only by certified applicators — choose "Other finish" and enter the coverage from the product's data.
Pool coping
Coping units — natural stone, precast, brick, cantilevered concrete — vary by product and supplier. Curved pools need radius pieces whose effective length along the edge differs from their nominal length; the tool says so rather than hiding it.
Frequently asked questions
How much concrete or gunite is in a pool shell?
Floor area times floor thickness, plus wall area times wall thickness, converted to cubic yards. The calculator works out the areas from your pool's shape and depths; the thicknesses must come from your pool's plans or engineer. Add the rebound and placement allowance your shotcrete or gunite contractor uses to get an order volume.
How thick should a pool shell be?
This calculator does not say, deliberately. The American Shotcrete Association states that pool wall thickness is part of the pool engineer's design — it depends on the soil, the depth, the reinforcement and the code where you build. There is no default thickness here, and shell volume is not calculated until you enter the thicknesses from your plans.
Why is there no default rebound percentage?
Shotcrete loses material that bounces off the surface during spraying, and dry-mix gunite generally loses more than wet-mix. But the governing guide is not publicly readable and the figures we could find disagreed with each other and could not be traced to a primary source. Your contractor knows the figure for their equipment and crew; enter theirs.
How many bags of pool plaster do I need?
The interior area — floor plus walls — divided by the coverage of one bag, rounded up. SGM publishes 22–25 square feet per 80 lb bag for Pool Brite plaster and Diamond Brite quartz. The calculator buys at the low end, 22, because SGM notes that surface roughness reduces coverage and running out part-way through a pool finish is far worse than a spare bag. The count at the high end is shown beside it. For any other finish, enter the coverage from its data sheet.
How much coping do I need?
The pool's perimeter divided by the length each piece covers plus the joint, rounded up. Round and oval pools need curved or cut pieces along the curves, so enter the length each piece covers along the edge as your supplier quotes it.
How many gallons of water does a pool hold?
Surface area times average depth gives cubic feet, and a cubic foot is 1728 ÷ 231 = 7.48 US gallons. For a rectangle with different shallow and deep ends the calculator assumes one even slope between them, and says so.
What about freeform, kidney or pools with a deep hopper?
Use the Custom shape and enter the floor area, wall area and perimeter from the plans. Approximating a freeform pool as a rectangle or oval, or a hopper as an even slope, would misstate every quantity that depends on the areas.
What about the pool deck?
Measure the deck as an area on the same workspace and turn on Pavers. It gets its own base, bedding sand and edging quantities.
What does this calculator not determine?
It never determines structural shell thickness, reinforcing steel, bar size or spacing, concrete strength or mix design, soil bearing, hydrostatic or groundwater design, structural wall or floor design, plumbing, equipment or electrical sizing, bonding or code compliance. It turns the dimensions you enter into material quantities, and nothing more.
Sources
- SGM Pool Brite — product page — SGM, Inc. (manufacturer). Each 80 lb bag covers approximately 22–25 sq. ft. at a minimum ⅜–½ in.; surface roughness affects coverage.
- SGM Diamond Brite — product page — SGM, Inc. (manufacturer). Each 80 lb bag covers approximately 22–25 sq. ft. at a minimum ⅜–½ in.; surface roughness affects coverage.
- American Shotcrete Association — Pool FAQs — American Shotcrete Association. "The pool wall thickness is a part of the pool engineer's design." Shotcrete is a placement method for concrete.
Other calculator websites are never cited. See the methodology page.
Last reviewed September 16, 2026.
Related
- Hardscaping Calculator — the pool, its deck and any walls on one order sheet.
- Paver Calculator — the pool deck.
- Concrete Calculator — a poured concrete deck or equipment pad.