# 12x20 inground pool: size, cost and what it looks like

Updated 2026-10-11.

A 12x20 inground pool is 240 square feet of water with 64 feet of edge, and holds about 8,100 gallons at a 4.5 foot average depth. It tops the 10x16 to 12x20 range one builder's guide gives for plunge and cocktail pools. The pool alone runs $22,000 to $60,000 at national planning rates.

## A 12x20 is 240 square feet, a 12x24 with four feet cut from the length

A 12x20 is as wide as a 12x24 and four feet shorter. That takes 48 square feet out of the water, and a 12x24 holds about 20 percent more. At twenty feet it is two and a half fence panels long and one and a half wide.

The picture is an AI concept image of a 12x24 in a narrow city yard, the closest size we have pictured, so a real 12x20 is a little shorter than the one shown. Scale is the usual worry with a small pool, whether it will look right in the yard, and the scale plan on this page draws the true outline next to its neighbours.

## A 12x20 suits sitting, cooling off and a few strokes, with a patio left over

One California pool builder's size guide places 12x20 at the top of a range of 10x16 to 12x20 feet for plunge and cocktail pools, and says pools that size suit smaller yards and tighter budgets. It describes them as good for cooling off and socializing without using up most of the outdoor space, and says a 12x20 still leaves room for in-pool seating and a usable patio.

Ask your builder whether twelve feet of width leaves room for a seat or a shelf along one side with open water beside it. Length is the limit: one pool maker's guide puts lap-focused small pools at 20 to 28 feet, so a 12x20 is at the short end, and says soaking needs about three feet of depth where laps need four to five. Decide which of the two you want before you choose depth, and [a cocktail pool](https://rendersplash.com/pool-features#cocktail-pool) is the version built for sitting.

By the quarter-of-the-yard rule a 12x20 suits a yard of about 950 square feet. With the 6 feet of clear space all round that a California builder's guide recommends, the footprint is 768 square feet. The pool maker also advises building no larger than a 12x24 on a lawn of 1,200 square feet or less, so a 12x20, 48 square feet smaller than a 12x24, sits inside that limit.

## A 12x20 costs less to build than a 12x24, and a quote shows by how much

Cost follows water area and edge, so the 12x20 sits below the 12x24 on every line in the table: a smaller pool, less coping, a smaller deck border and a shorter fence run. The table prices each line at published rates. It leaves out permits, engineering, a heater and a cover, and your town and soil move all of it.

Ask each builder to price a 12x20 and a 12x24 on the same lines, and compare the gap with the water you would give up. The [12x24 page](https://rendersplash.com/pool-sizes/12x24) shows the published prices that disagree for that size, and the [cost page](https://rendersplash.com/inground-pool-cost#line-items) lists every line a quote should carry. We re-read the two size guides this page leans on on October 11, 2026.

## What a 12x20 inground pool costs, line by line

| Line | Planning range | How it is worked out |
|---|---|---|
| The pool | $22,000 to $60,000 | 240 sq ft of water at $90 to $250 a square foot (shell, excavation, plumbing, equipment, plaster). |
| Coping | $500 to $3,500 | 64 linear ft of water edge at $6 to $55 a foot, from plain concrete to travertine. |
| A 4 ft deck border all round | $1,000 to $26,000 | 320 sq ft at $3 to $80 a square foot installed, from pavers to composite decking. |
| Aluminum pool fence around that deck | $1,500 to $3,500 | 96 linear ft at $15 to $35 a foot installed. |
| All of the above, if your quote includes it | $25,000 to $95,000 | Rounded |

## Questions people ask

**How many gallons is a 12x20 pool?** About 8,100 gallons at a 4.5 foot average depth, or 7,200 to 9,000 at 4 to 5 feet. A plunge or cocktail pool is often shallower, which lowers the figure.

**Is a 12x20 inground pool big enough for a family?** For sitting, cooling off and playing, yes: one California builder's guide says a 12x20 leaves room for in-pool seating and a usable patio. It is short for laps at 2.5 fence panels long. If your yard has the room, compare it with a [12x24](https://rendersplash.com/pool-sizes/12x24).

**How much does a 12x20 inground pool cost?** The pool alone comes to $22,000 to $60,000 at national planning rates, and with coping, a four foot deck border and a fence the range reaches $25,000 to $95,000. Ask local builders for itemised written quotes. See [inground pool cost, line by line](https://rendersplash.com/inground-pool-cost#line-items).

## Sources and date checked

Links checked 2026-10-11. A planning range from published sources, not a quote.

- [The California Pool & Spa Atelier, a California pool builder, swimming pool size chart, 2026](https://thecpsa.org/blog/swimming-pool-size-chart/)
- [Pool Research, pool volume, undated](https://poolresearch.com/pool-volume-calculator/)
- [Latham Pool, how small is too small, 2024](https://www.lathampool.com/blog/research/how-small-of-a-pool-is-too-small/)
- [HomeAdvisor, in-ground pool cost, 2026](https://www.homeadvisor.com/cost/swimming-pools-hot-tubs-and-saunas/inground-pool)
- [Fixr, gunite and concrete pool, 2025](https://www.fixr.com/costs/inground-gunite-concrete-swimming-pool)
- [Pool Research, plunge pool cost, undated](https://poolresearch.com/plunge-pool-cost/)
- [Pool Research, pool coping cost, 2026](https://poolresearch.com/coping-cost/)
- [HomeAdvisor, travertine pavers, 2026](https://www.homeadvisor.com/cost/outdoor-living/travertine-pavers-install/)
- [HomeAdvisor, pool deck cost, 2026](https://www.homeadvisor.com/cost/swimming-pools-hot-tubs-and-saunas/pool-deck)
- [Fixr, pool fence, 2025](https://www.fixr.com/costs/swimming-pool-fence)

Every picture on these pages is an AI concept image, not a built pool, and its proportions are not measured. Where a size has no picture of its own we show the closest one and say so in the text. Cost ranges are planning numbers from published guides at national rates, not quotes.

Pricing the whole job? See [inground pool cost, line by line](https://rendersplash.com/inground-pool-cost#line-items).

Will a 12x20 fit your yard? Try it in the planner: https://rendersplash.com/pool-sizes?s=12x20#size-planner

See a 12x20 in your own yard with the free visualizer: https://rendersplash.com/pool-visualizer