Contact
Report a calculation problem, suggest a correction, or send general feedback.
Email hello@percentswift.com for questions, bug reports, formula verification inquiries or editorial corrections.
Reporting a calculation or formula issue
Every calculator and guide on PercentSwift is tested against our shared exact-decimal engine. If a calculation, rounding step or worked example looks wrong or unclear, please include the following details so we can reproduce it immediately:
- The exact page URL or the language and calculator mode you were using (for example, Reverse Percentage or VAT Calculator).
- The input values you entered and the regional or rounding settings selected at the time.
- The result shown on screen and the result or formula you expected to see, along with any official source if your question relates to a regional VAT or sales tax preset.
Editorial and guide feedback
Our 100 percentage guides cover everyday calculations across finance, shopping, school grades, business metrics, statistics and spreadsheets. If you spot a typo, a broken link, a spreadsheet formula that behaves differently in your locale, or a topic that needs a clearer worked example, write to us with the article title and section heading.
Privacy, cookies and advertising inquiries
For questions about how browser preferences, optional analytics (Google Analytics 4) or advertising cookies (Google AdSense) operate on PercentSwift, please consult our Privacy policy first or contact us at hello@percentswift.com. You can change your analytics consent at any time using the “Privacy choices” link in the site footer.
What not to send
Please do not include confidential financial statements, tax identification numbers, payroll records, account numbers or other sensitive personal data in your email. Plain sample numbers are all we need to check any calculation. PercentSwift provides mathematical tools and general educational guides and cannot provide individualized tax, legal, accounting or investment advice.