How many litres is my pool?

Multiply the water surface area in square feet by the average depth in feet, then multiply by 28.3168, the number of litres in a cubic foot under Canada's Weights and Measures Act. A 14 by 28 foot rectangular pool at 4 feet average depth works out to 44,400 litres, which is the figure Pool Supplies Canada and Pioneer Family Pools both publish for that size.

How do I find the average depth of a pool?

Add the depth of the water at the shallow end to the depth at the deep end and divide by two. Pool Supplies Canada states the rule that way on its Canadian litre chart, and Leslie's works the same example: a 3 foot shallow end and an 8 foot deep end give 5.5 feet average. Measure the water, not the wall, because an above-ground pool is normally filled several inches below the top rail.

Are pool gallons Canadian gallons or American gallons?

Both are in use here and they are 20 percent apart, which is why this calculator prints them separately. A Canadian gallon is 4.54609 litres in Schedule II of the Weights and Measures Act. A US liquid gallon is 3.785412 litres per NIST. Pool equipment and chemical labels sold in Canada are usually rated in US gallons because they are made for the American market, so read the label before you dose.

Why does an above-ground oval hold more than an inground oval the same size?

They are different shapes. An inground oval is a true ellipse, and the published formula takes pi divided by four of the length by width box. An above-ground oval is a stadium: two straight sides with a half circle at each end, which fills more of the same box. On a 15 by 27 foot pool at 4 feet the stadium holds about 40,400 litres against roughly 36,100 for the ellipse, so picking the wrong one puts every dose out by more than a tenth.

How accurate is a kidney pool volume?

Less accurate than the other shapes, and honestly so. The published kidney formula multiplies the two bulge widths added together by the length and by a 0.45 shape factor, which is an approximation of a curve that varies from pool to pool. Leslie's publishes it as an approximate volume. If you dose to the litre on a kidney pool, work from a water meter reading taken while filling instead.

Why does knowing the volume matter?

Almost every number in pool ownership is per litre. Chlorine, shock, alkalinity increaser and algaecide are all dosed against volume, a salt system is rated in litres, and a filter and a heater are sized against volume and surface area. Getting the volume wrong by a fifth means every chemical you add for the rest of the season is wrong by a fifth.

How many litres is your pool?

Last updated:August 26, 2026By The Pool Trade Desk

Water surface in square feet, times the average depth in feet, times 28.3168 litres per cubic foot. Pick your shape and the answer appears as you type.

How much water does your pool hold?

What shape is the pool?

RectangularStraight sides and square cornersRoundOne diameter, usually one depthOval, above groundStraight sides with a rounded end at each finishOval, ingroundA true ellipse, curved the whole way roundKidneyTwo bulges of different width, waisted in the middle

Length (feet)

Width (feet)

Depth of water at the shallow end (feet)

Measure the water, not the wall height.

Depth of water at the deep end (feet)

Flat bottom? Put the same figure in both boxes.

Your pool holds about

50,000litres

Cubic metres: 50.0
Imperial gallonsThe Canadian gallon, 4.54609 litres: 11,000
US gallonsWhat most pool equipment and chemical labels are rated in: 13,200
Water surfaceThe figure a heater and a solar cover are sized on: 392 sq ft
Average depthShallow end and deep end, added and halved: 4.5 ft

The arithmetic: 28 ft long x 14 ft wide = 392 sq ft of water, x 4.5 ft average depth, x 28.316846592 litres per cubic foot.

Steps, benches, a tanning ledge and a spa spill all move the real figure, and a vinyl liner pool is measured to the water line rather than the coping. Treat the answer as accurate to a few percent, which is close enough for dosing and far closer than guessing.

How the calculator gets to a number

Method

Every shape here is two steps. First the water surface, in square feet. A rectangle is length by width. A round pool is pi divided by four, times the diameter squared, which is the published round formula written the short way. An inground oval is the same pi over four rule applied to the length by width box. A kidney adds the two bulge widths, multiplies by the length, and takes 0.45 of the result. Then the surface is multiplied by the average depth to give cubic feet, and cubic feet become litres at 28.3168 each.

The above-ground oval is the shape that catches people out, so it is a separate choice rather than a footnote. An above-ground oval pool is not an ellipse. It is a stadium: a straight-sided middle section with a half circle bolted on at each end. The calculator works out the straight part and the two half circles separately and adds them, which is exact geometry with no shape factor in it at all. The check that it is right is arithmetic anyone can repeat: this method gives 40,404 litres for a 15 by 27 foot pool at 4 feet, and both Pool Supplies Canada and Pioneer Family Pools publish 40,400 for exactly that pool.

What the tool cannot see is everything that is not a smooth box of water. Steps and a tanning ledge take water out; a spa that spills into the pool and a deep diving well put it back. On a vinyl liner pool the measurement that matters is to the water line, which sits below the coping. A few percent either way is the honest accuracy here, and a few percent is close enough for every dose you will ever mix. If you need it exact, read your water meter before and after a fill.

One Canadian wrinkle worth knowing. Almost every pump, filter, heater, salt cell and chemical bottle sold in this country is built for the American market and rated in US gallons, while the water itself is sold, metered and talked about in litres. That is why this page prints litres, cubic metres, Canadian gallons and US gallons side by side instead of picking one and hoping.

Frequently asked questions

How many litres is my pool?: Multiply the water surface area in square feet by the average depth in feet, then multiply by 28.3168, the number of litres in a cubic foot under Canada's Weights and Measures Act. A 14 by 28 foot rectangular pool at 4 feet average depth works out to 44,400 litres, which is the figure Pool Supplies Canada and Pioneer Family Pools both publish for that size.
How do I find the average depth of a pool?: Add the depth of the water at the shallow end to the depth at the deep end and divide by two. Pool Supplies Canada states the rule that way on its Canadian litre chart, and Leslie's works the same example: a 3 foot shallow end and an 8 foot deep end give 5.5 feet average. Measure the water, not the wall, because an above-ground pool is normally filled several inches below the top rail.
Are pool gallons Canadian gallons or American gallons?: Both are in use here and they are 20 percent apart, which is why this calculator prints them separately. A Canadian gallon is 4.54609 litres in Schedule II of the Weights and Measures Act. A US liquid gallon is 3.785412 litres per NIST. Pool equipment and chemical labels sold in Canada are usually rated in US gallons because they are made for the American market, so read the label before you dose.
Why does an above-ground oval hold more than an inground oval the same size?: They are different shapes. An inground oval is a true ellipse, and the published formula takes pi divided by four of the length by width box. An above-ground oval is a stadium: two straight sides with a half circle at each end, which fills more of the same box. On a 15 by 27 foot pool at 4 feet the stadium holds about 40,400 litres against roughly 36,100 for the ellipse, so picking the wrong one puts every dose out by more than a tenth.
How accurate is a kidney pool volume?: Less accurate than the other shapes, and honestly so. The published kidney formula multiplies the two bulge widths added together by the length and by a 0.45 shape factor, which is an approximation of a curve that varies from pool to pool. Leslie's publishes it as an approximate volume. If you dose to the litre on a kidney pool, work from a water meter reading taken while filling instead.
Why does knowing the volume matter?: Almost every number in pool ownership is per litre. Chlorine, shock, alkalinity increaser and algaecide are all dosed against volume, a salt system is rated in litres, and a filter and a heater are sized against volume and surface area. Getting the volume wrong by a fifth means every chemical you add for the rest of the season is wrong by a fifth.

Where these figures come from

Provenance

Two of these are statute and the rest are published industry formulas and charts. Nothing on this page is a price, so nothing on it needed a market range.