Comparison

Pool Calc vs Pool Math

Pool Math is the calculator from TroubleFreePool, and many pool owners learned their chemistry from that forum. Pool Calc works from the same kind of readings, with free chlorine targets that follow your stabilizer, and gives a single pool every feature for free. Here is what each one does, and where Pool Math is still the better pick.

Prices, features and ratings checked on 28 October 2026.
App Store rating as shown on 28 October 2026: 3.6 stars from 287 ratings on the US App Store.

The short answer

Pool Math is a good calculator with a large community behind it, and Premium is cheap. Pool Calc is for owners who want the full log, charts and reminders free for their one pool, targets that never reset, and a dose plan written for the bottles they own. Pool service techs also get clients, a route and service reports on Plus or Pro.

At a glance

From each app's own App Store page and website, checked on 28 October 2026. "Not listed" means we found no mention of it there, not that the feature is missing.
Feature	Pool Calc	Pool Math
Price for one pool	Free, every feature	Free calculators; $7.99/year Premium for the full log
Test log history	Yes Full history, free	Yes Unlimited with Premium
Charts	Yes 7 days to all time, free	Not listed
More than one pool or spa	Yes Plus (5) or Pro (unlimited)	Yes Premium (unlimited configurations)
Dose plan in order	Yes Ordered plan, large doses split	Yes Chemical addition calculators
Your own products at any strength	Yes Any brand, any strength	Yes Bleach price calculator; product options not listed
Siri Shortcuts	No	Yes
Water balance (CSI)	Yes CSI gauge	Yes CSI calculator
Non-chlorine shock (MPS)	Yes	Not listed
Maintenance log (backwash, filter, salt cell)	Yes	Yes
Reminders	Yes Free	Yes Premium
Backup and sync	Yes Free iCloud backup	Yes Premium cloud sync
CSV export	Yes Free, plus PDF	Yes Premium import/export
Account to sign up for	None	Not listed
Clients, route and service reports	Yes Plus and Pro	Not listed
Community forum	No	Yes TroubleFreePool
Platforms	iPhone (iOS 18 or later)	iPhone, iPad, Apple silicon Mac, Android

Pricing

Our app

Pool Calc

Free$0Every feature for one pool and its attached spa: full history, charts, CSI, reminders, PDF and CSV export, iCloud backup.
Plus$1.99 a month, $14.99 a year or $39.99 onceUp to 5 pools plus the pro tools. 1-week free trial on the yearly plan.
Pro$9.99 a month or $79.99 a yearUnlimited pools plus the pro tools. 1-month free trial on the yearly plan.

Prices on the App Store at launch. Pricing is per person, not per pool.

Pool chemistry app

Pool Math

Free$0Calculators for pH, free chlorine, calcium hardness, salt, total alkalinity, borates and CSI, plus tracking and a summary page.
Premium$7.99/yearAdds unlimited test log history, maintenance reminders, cloud and multi-device sync, unlimited pool/spa configurations, and CSV import/export.

Free download with one in-app purchase.

Prices as listed on 28 October 2026. Source

Pool Math is cheaper if you pay: $7.99 a year for Premium against Pool Calc Plus at $14.99 a year. The difference is in what's free. Pool Math's listing puts unlimited log history, reminders and sync in Premium. Pool Calc puts all of those in the free plan and charges only when you add a second pool.

One pool, every feature free

Most people own one pool. In Pool Calc, that pool and its attached spa get the full log, every chart range, the CSI gauge, unlimited reminders, PDF and CSV export, widgets and iCloud backup without paying. You only pay to look after more pools, and if a subscription ends, nothing is deleted.

Targets that stay put

Pool Calc stores your custom targets until you choose "Reset to recommended", and the free chlorine target follows your CYA until you set your own. One screen takes the whole test, with "Same as last" for slow readings like CYA and calcium, and a draft is saved on every change.

A plan you can follow at the pool

After a test, Pool Calc shows each dose in the order to add it, for the products on your shelf at the strength on their labels. Large acid and chlorine doses are split into smaller additions with a wait between them. "Mark as added" logs the dose and sets a retest reminder.

What Pool Math Users Complain About

Paraphrased from public reviews. Each one links to where it was posted and gives the month it was written.

Custom targets reset. A 2022 App Store reviewer said their custom FC, pH, TA and CYA targets went back to defaults each time they reopened results, while praising the math and the reminders (App Store review, June 2022).

Pool Calc approach: custom targets persist until you reset them yourself.
The free version feels too limited for one pool. A Google Play reviewer in August 2026 said the free version keeps only one day of logs and found the subscribe prompt frustrating as a single-pool owner (Google Play review, August 2026).

Pool Calc approach: one pool gets the full history and every other feature free.
No place for non-chlorine shock. A 2022 App Store reviewer asked for MPS and more spa-specific options and was logging MPS as something else or in a note (App Store review, April 2022).

Pool Calc approach: MPS is a regular product with its own dose and log entry. Hot tubs on their own have a dedicated app, Spa Calc.

When Pool Math is the better choice

You follow the TroubleFreePool method and want the app that comes from the same people, with the forum one tap away.
You want the cheapest paid plan for several pools and spas: $7.99 a year.
You want an iPad, Mac or Android version. Pool Calc is iPhone only.
You already have years of logs in Pool Math and don't want to move them.

Questions people ask

Is there a free alternative to Pool Math?

Pool Calc gives your first pool and its attached spa every feature for free, including the full log, charts, the CSI gauge, reminders, PDF and CSV export and iCloud backup. It is on the App Store at launch. Orenda's app is also free, as a dosing and LSI calculator.

Is Pool Math worth paying for?

At $7.99 a year, Premium is cheap, and it adds unlimited log history, reminders, sync and more than one pool or spa (App Store listing, 28 October 2026). If you follow the TroubleFreePool method and use the forum, it fits that method closely.

Does Pool Math work for a hot tub?

Pool Math's Premium listing includes unlimited pool/spa configurations. For a hot tub on its own, our sister app Spa Calc is built for tubs: a soak check, bromine, doses in teaspoons and a drain countdown.

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References

Pool Math and TroubleFreePool are trademarks of their respective owners. Pool Calc is not affiliated with them. Information checked on 28 October 2026; prices and features change. Corrections: [email protected]