Terms of service

Plain terms for a calculator app. By installing or using Calctro you agree to them. Last updated 5 November 2026.

Using the app

Your licence. You may install and use Calctro on devices you own or control, for personal or work use. The licence is personal to you and non-exclusive, and the app remains ours.
What you agree not to do. Don't copy, resell or redistribute the app, and don't reverse engineer it except where the law allows you to. Don't use it to break the law.
Your data. Registers, programs and settings are stored on your device and we have no copy of them. If you delete the app or lose your device, they are gone. Our privacy page explains what is collected and when.
Changes to the app. We may update, change or withdraw the app or any calculator model in it. Some functions may not be available yet.

Calculators can be wrong. We work hard to get results right, but we don't promise that the app is free of errors or that every result will match any particular calculator. Check any result that matters before you rely on it.
Not professional advice. Calctro is a tool for doing arithmetic. Nothing in it is financial, tax, legal, engineering or other professional advice.

Our liability. The app is provided as it is. As far as the law allows, we aren't liable for loss arising from your use of the app or from relying on its results, including financial loss, loss of profit or loss of data. Our total liability to you is limited to the amount you paid for the app.

Purchases. Any price, payment or refund is handled by the store you got the app from, under that store's rules.
Apple and Google. These terms are between you and us, not Apple or Google, and we alone are responsible for the app and its support. If you got the app from the App Store, your use must also follow Apple's Usage Rules, and Apple and its subsidiaries may enforce these terms as third-party beneficiaries.

Changes to these terms. We may update these terms and will post the new version here with a new date. If you keep using the app after that, the new terms apply.
Ending these terms. You can stop at any time by deleting the app. If you break these terms, your licence ends.
Governing law. These terms are governed by the law of England and Wales, and its courts have jurisdiction. If you are a consumer living elsewhere, you keep the protections of the law where you live and may bring a claim in your local courts.

Calctro is not affiliated with HP Inc.