Free: The True Pool Volume Workbook
Your pool probably does not hold what you think it holds
Ask ten pool owners how many gallons they have and nine will give you a number they got from a builder, a real estate listing, or the side of a box. Most of those numbers are wrong, and some are wrong by 20% or more.
It matters because every dose you will ever add has that number in it. Get the volume wrong and every chemical is wrong by the same proportion, permanently.
The classic version: an owner added twelve 40 lb bags of salt to what they believed was an 8,403 gallon pool and the level barely moved. The answer from Inyo was not about salt or dissolving. It was to go and recalculate the pool size.
What is in the workbook
Measurement worksheets for rectangles, circles, ovals and freeform shapes, with space to record what you measured so you are not redoing it next year.
The average depth method done properly. A flat shallow end, a slope and a hopper do not average the way people assume. Taking a straight average of your shallow and deep depths overstates most inground pools, in our worked example by 14%. The area-weighted method is three lines of arithmetic and it is in here.
Above-ground and frame pool reference tables, because if yours is a standard size you can skip the measuring entirely.
The water meter cross-check, a ten minute independent verification that catches measurement mistakes.
The salt trace method. This is the part nobody else has written up. Add a precisely known weight of salt, wait for it to distribute, measure the rise in salinity, and work backward to your actual volume. It measures the water rather than the hole, which makes it the most accurate figure you will ever have for your own pool. Owners are trying to invent this themselves on the forums, including a whole Trouble Free Pool thread asking whether you can calculate pool volume by adding one bag of salt. The workbook has the procedure, the conditions it needs to be accurate, and the error margins.
A builder’s-claim comparison page, so you can see how far off the number you were given actually was.
PDF, free, no catch beyond an email address.
What you get afterwards
The workbook arrives immediately. After that you will get occasional emails when we publish something useful about salt pools, and you can leave with one click. We do not sell or share the list, and we do not send daily anything. Our privacy policy is short and says the same thing.
If you would rather just get a number now
The pool volume calculator will give you gallons in about thirty seconds from your shape and dimensions, no email needed. The workbook is for when you want a figure you would bet a season of chemistry on.