# 12x24 vs 15x30 inground pool: how much bigger is the 15x30?

Updated 2026-10-10.

A 15x30 inground pool has 450 square feet of water and a 12x24 has 288, so the 15x30 is 1.56 times the size. It holds about 15,100 gallons against 9,700, and has 18 more feet of edge. Here are both in a backyard, and what the difference costs.

| | 12x24 | 15x30 |
|---|---|---|
| Water surface | 288 sq ft | 450 sq ft |
| Edge | 72 ft | 90 ft |
| Gallons at 4.5 ft | 9,700 | 15,100 |

The lines a quote should carry are on the [inground pool cost page](https://rendersplash.com/inground-pool-cost#line-items); the yearly bill is in [what a pool costs to run](https://rendersplash.com/inground-pool-cost#running-cost).

## Questions people ask

**How much bigger is a 15x30 than a 12x24?** 162 square feet of water, which is 1.56 times the area. The 15x30 is 6 feet longer and 3 feet wider, and holds about 5,400 more gallons at a 4.5 foot average depth.

**How much more does a 15x30 cost than a 12x24?** At national planning rates the pool line is $26,000 to $72,000 for a 12x24 and $41,000 to $113,000 for a 15x30, and rounded to the nearest $5,000 the pool alone comes to $25,000 to $75,000 against $40,000 to $115,000. The gap widens with the edge, since coping, deck and fence all scale with the perimeter. The [cost page](https://rendersplash.com/inground-pool-cost#line-items) prices those lines, and the [running cost](https://rendersplash.com/inground-pool-cost#running-cost) grows with the water too.

**Is a 15x30 worth it over a 12x24?** If the yard allows it and the budget does too, the larger pool gives you room for a shelf or a spa; the smaller one leaves more yard. Mark both outlines on your lawn and compare how much deck and grass is left. The [guide](https://rendersplash.com/pool-sizes/what-size-pool-do-i-need) walks through it.

## Sources and date checked

Links checked 2026-10-06. 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.