Pool Volume Calculator

All tools

Calculate how much water your swimming pool holds — pick the shape, enter the dimensions and depth to get the volume in gallons, litres and cubic metres, plus fill time.

ft
ft
ft
ft
ft
ft
ft
ft
gpm
Water volume – US gallons
Litres –
Cubic metres –
Approx. fill time –
Volume uses average depth × surface area; a sloped floor uses the mean of the shallow and deep ends. Gallons are US gallons. Fill time is an estimate at a constant flow rate.

About Pool Volume Calculator

The pool volume calculator works out how many gallons of water your swimming pool holds. Pick the shape — rectangle, round or oval — enter the dimensions and depth, and the volume appears in US gallons, litres and cubic metres, so it is ready for whichever chemical dosing chart or water bill you are reading.

Volume is surface area multiplied by average depth. For pools with a sloped floor, switch the depth mode to enter the shallow and deep ends separately; the calculator uses their mean as the average depth. Enter a fill rate and it also estimates how long the pool will take to fill from a hose or supply line.

Knowing the true volume is the starting point for pool ownership: chlorine and salt doses, pump and filter sizing, and heater selection all depend on it. This free tool answers the question in seconds — no wading through unit conversions.

How to use Pool Volume Calculator

  1. Select the pool shape: rectangle, round or oval.
  2. Choose metric or imperial units and enter the dimensions — length and width, diameter, or the two oval axes.
  3. Enter the average depth, or switch to shallow and deep end depths for a sloped floor.
  4. Optionally add a fill rate to estimate the fill time.
  5. Read the volume in US gallons, litres and cubic metres.

Frequently asked questions

Multiply the surface area by the average depth — this calculator does it for you from the shape and dimensions, and converts the result into US gallons, litres and cubic metres automatically.

Choose the shallow-and-deep depth mode and enter both figures. The calculator averages them, which closely matches the true volume of a pool with a steadily sloping floor.

Chemical dosing — chlorine, salt, pH adjusters — is specified per volume of water, and pumps, filters and heaters are sized by it too. An accurate volume prevents both under- and over-dosing.

It assumes a constant flow at the rate you enter. Real fills can slow as pressure varies, so treat the figure as a planning estimate rather than a precise schedule.

US gallons. If you need imperial gallons, use the litres figure and divide by 4.546 — one imperial gallon is about 20% larger than a US gallon.
Share this
Related Tools
Universal Unit Converter Convert length, area, volume, weight, temperature, time, speed, angle, pressure, energy, power, data and more across 16 categories — instantly and for free. Free
Fuel Cost Calculator Estimate the fuel cost of any trip in metric or imperial units. Add a round trip, split the cost between passengers and see the cost per mile or kilometre. Free
Electricity Cost Calculator Find out how much an appliance costs to run. Enter its power in watts or kilowatts, how long it runs and your electricity rate to see daily, monthly and yearly costs. Free
Bill Split Calculator Split a restaurant or group bill fairly. Add tax and tip, set the number of people and see the grand total plus exactly what each person owes. Free
Profit Margin Calculator Calculate gross profit, profit margin and markup from your cost and selling price, or work backwards from a target margin to find the price you should charge. Free
Conversion Rate Calculator Measure your funnel performance. Enter visitors and conversions to get your conversion rate, plus revenue per visitor, average order value, cost per acquisition and ROAS. Free
Need help?
Found an issue with this tool? Let our team know.
Report an issue

Add this free tool to your own website — copy and paste the code below.