Pool & Spa Filter Size Calculator
Get the right sand, cartridge or DE filter for your pool or spa in seconds. Enter your dimensions, or skip ahead if you already know your water volume.
1. Pool Size
2. Filter Requirements
Based on your water volume and selected turnover time. For best results, choose a filter at or above this size.
Shop Compatible Filters →How the Calculator Works
Select Pool or Spa, then pick the shape that matches your setup.
Provide dimensions in metres or skip ahead with your known water volume.
See a recommended sand/glass filter by litres, or cartridge/DE sizing by flow rate.
Frequently Asked Questions
How is my pool or spa volume calculated?
We multiply the surface area of your shape by the average depth, then convert cubic metres to litres. One cubic metre equals 1,000 litres.
What does turnover time mean?
It is the number of hours used to circulate the full water volume. Australian residential pools commonly use a 6–8 hour turnover guide, while spas usually need shorter turnover times.
Which filter type is best for me?
Sand filters are low-maintenance, cartridge filters offer finer filtration and save water, and DE filters provide very fine filtration but need more upkeep.
Can I oversize my filter?
Yes. Choosing a filter rated above the calculated flow is generally safe and can reduce strain on the system. If you are between sizes, choose the next size up.