Terms that respect your time.
These terms govern your use of DigitSum. By accessing the site, you agree to these terms.
Last updated: March 2026
1. Acceptance of terms
By accessing or using DigitSum (digitsum.com), you agree to be bound by these Terms of Service. If you do not agree, please do not use the site.
2. Operator
DigitSum is operated by Jan Křenek, a self-employed entrepreneur registered in the Czech Republic, IČO 17397979. Contact information is available on the Contact page.
3. Service description
DigitSum provides free online calculators for finance, tax, income, health, math, conversions, productivity, developer, business, and everyday planning topics. Many calculators run locally in your browser and are designed for educational and planning use.
4. Calculation accuracy disclaimer
THE INFORMATION AND TOOLS ON THIS WEBSITE ARE PROVIDED AS IS WITHOUT ANY WARRANTY OF ANY KIND. Calculator results are estimates for informational and educational purposes only. DigitSum does not guarantee that every result, data source, threshold, exchange rate, tax estimate, or assumption is complete, current, or suitable for your situation.
5. No professional advice
DigitSum does not provide financial, tax, legal, medical, engineering, or other professional advice. Do not rely on calculator outputs for critical decisions without checking the formula, verifying the inputs, and consulting a qualified professional where appropriate.
6. User responsibilities
You are responsible for the accuracy of the values you enter, the assumptions you choose, and how you interpret results. You agree not to misuse the site, overload the service, scrape it in a way that harms availability, or use the tools for unlawful purposes.
7. Advertising disclosure
DigitSum may display advertising, including Google AdSense ads. Advertising helps keep the calculators free. Ads do not influence calculator formulas, assumptions, results, or editorial methodology.
8. Privacy and data
Your use of DigitSum is also governed by our Privacy Policy. Calculator inputs are designed to be processed locally in your browser and are not intentionally collected or stored on our servers.
9. Intellectual property
All content, design, branding, and code on DigitSum are owned by or licensed to DigitSum unless otherwise stated. You may use the calculators for personal and internal business planning. Reproducing, republishing, or redistributing site content at scale without permission is prohibited.
10. Availability and changes
DigitSum is provided on an "as is" and "as available" basis. We may modify, suspend, or discontinue any part of the service, update calculator logic, change assumptions, or revise content when sources or product requirements change.
11. Limitation of liability
To the maximum extent permitted by Czech and EU law, DigitSum and its operator are not liable for indirect, incidental, consequential, or special damages arising from your use of the site or reliance on calculator output. Nothing in these Terms excludes liability that cannot legally be excluded, including liability for intent, gross negligence, or personal injury where applicable.
12. Third-party links and services
DigitSum may link to third-party references, source material, policy pages, or service providers. We are not responsible for third-party content, availability, or privacy practices.
13. Governing law
These Terms are governed by the laws of the Czech Republic. For consumers domiciled in another EU Member State, mandatory provisions of the consumer-protection law of their country of residence are not affected.
14. EU online dispute resolution
European consumers may find information about online dispute resolution through the European Commission platform at ec.europa.eu/consumers/odr/.
15. Updates to these terms
We may update these Terms from time to time. The updated date on this page indicates the current version. Continued use of the site after updates means you accept the revised Terms.
16. Contact
If you have questions about these Terms, calculator disclaimers, corrections, or the operator identity, contact us through the Contact page or the email address shown in the footer.