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Triangular Pool Volume Calculator

Triangular pools tuck into a corner of a yard and hold about half the water of a rectangle with the same footprint. Measure the base and the straight height to the far point.

Triangular pool with the measurements needed for a volume calculation

Calculate your triangular pool volume

1. Pick your pool shape

A three sided pool, often tucked into a corner of a yard.

2. Enter your measurements

Measure in feet or meters. You always get gallons and litres back.

Straight distance from the base to the far point.

3. Set your depth

This shape normally has a flat floor, so one water depth is enough.

Measure to the water line, not the top of the wall.

Your pool volume result

Pool volume

4,788 gallons

18,123 litres

Cubic feet
640 cu ft
Cubic metres
18.1 m3
Surface area
160 sq ft
Average depth
4.00 ft
Pool shape
Triangular
How we calculated this

Shape: Triangular. Dimensions used: Base 20 ft, Height 16 ft. Depth: 4 ft throughout. Formula: Volume = (base x height) / 2 x depth. Conversion: cubic feet x 7.48 = US gallons, gallons x 3.785 = litres, cubic feet x 0.0283 = cubic metres.

How the triangular pool volume calculator works

Area is base times height divided by two. The height is the straight distance from the base to the opposite point, measured at a right angle.

Multiply the area by the water depth for cubic feet, then by 7.48 for US gallons.

The formula

Volume = (base x height) / 2 x depth

Measure: Base, height, depth.

Worked example

A pool with a 20 foot base and a 16 foot height has an area of 160 square feet.

With 4 feet of water that is 640 cubic feet, close to 4,788 gallons or 18,120 litres.

Tips before you measure

The height is not the length of a slanted side. Measure straight in from the base to the far corner.

Rounded corners take a little area off, so subtract 3 to 5 percent if your triangle has soft points.

Triangular pool volume FAQs

What counts as the height?

The perpendicular distance from the base line to the opposite corner, not the sloping side length.

Does this work for a right angle triangle?

Yes. Use the two sides that meet at the right angle as the base and the height.

How do I handle a curved third side?

Treat it as freeform instead, or add 5 percent to the triangle result if the curve bows outward.

Other pool shapes

Not quite the right outline? The main pool volume calculator covers all 20 shapes with the same units and formulas.