A lap pool is long and narrow, built for swimming lengths rather than sitting in. The shape suits a narrow garden, and because it is usually a uniform depth, the volume is easy to calculate exactly.
The narrow shape has a practical consequence worth knowing about: water circulates less well down a long thin pool than a square one. Return jets at one end can leave the far end almost still, and still water is where algae starts.
A lap pool also has a high surface area relative to its volume, which means proportionally more evaporation and more heat loss than a compact pool holding the same water.
At a glance
| Characteristic | Typical |
|---|---|
| Typical length | 40 to 75 ft |
| Typical width | 8 to 10 ft |
| Depth | Usually uniform, 3.5 to 4.5 ft |
| Volume | Often less than it looks — narrow and shallow |
| Circulation | Needs attention; long pools develop dead ends |
Advantages and limitations
What works well
- Fits a narrow garden where a conventional pool will not.
- Built for exercise — proper lengths without turning constantly.
- Uniform depth makes volume, and every chemical dose, easy to get right.
- Often less water than a conventional pool of the same footprint.
- A swim jet can make a short lap pool swim like a long one.
What to weigh up
- Circulation is the weak point — the far end can go stagnant.
- High surface area for the volume, so more evaporation and heat loss.
- Not much use for playing, floating or entertaining.
- Usually too shallow for diving.
- Heating costs more per gallon than a compact pool because of the surface area.
Looking after one
- Brush the far end and the corners weekly — circulation is weakest where the returns cannot reach.
- Consider additional return fittings, or aim the existing ones to push water down the length.
- Run the pump for a full turnover; a long pool is less forgiving of a short schedule.
- Use a cover. The surface area that makes it evaporate is the same area a cover protects.
- Test as often as any other pool — the shape changes circulation, not chemistry.
What it costs to own
Cost tracks length and construction rather than being a category of its own. A lap pool is usually less to build than a large freeform pool, simply because it holds less water and has a simpler shape.
Heating is where the shape costs money. Heat is lost from the surface, and a lap pool has a lot of surface for the water it holds — so a cover matters more here than almost anywhere else.
Prices for pools vary enormously by region, access, ground conditions and specification, so no figure is quoted here. The Ownership Cost Calculator uses your own numbers instead of an average that would be wrong for most people.
Calculators for this pool
Questions people ask
How long does a lap pool need to be?
Forty feet is generally considered the practical minimum for swimming proper lengths; 45 to 60 ft is more comfortable. Below that, a swim jet is usually the better answer than a longer pool.
How many gallons is a lap pool?
Less than most people expect. A 45 × 8 ft pool at 4 ft deep holds about 10,800 gallons — well under a conventional family pool. Use the volume calculator for yours.
Do lap pools have circulation problems?
They can. Long narrow pools develop dead water at the end furthest from the returns. Extra return fittings, or aiming the existing ones along the length, fixes it.
Are lap pools cheaper to run?
Less water means fewer chemicals, but the high surface area means more evaporation and heat loss. Unheated, usually cheaper; heated, often not.