Frequently asked questions

QuickSum is a free online calculator hub offering 20+ calculators across finance, health, and everyday categories. All calculators run entirely in your browser — no account, no sign-up, and no data sent to any server.

Yes, completely free. You never need to create an account or pay for any feature — every calculator, article, and tool is available to everyone without limits.

No. Every calculator on QuickSum is available without registration. Your theme preference (light/dark) is saved locally in your browser.

QuickSum calculators use standard financial and scientific formulas (such as the standard loan amortisation formula, Mifflin-St Jeor for calories, and the US Navy method for body fat). Results are accurate for estimation purposes. However, real-world outcomes depend on many factors — always verify important financial or medical decisions with a qualified professional.

Yes. The currency converter fetches live rates from the Frankfurter API (powered by central bank data, including the ECB), with an automatic backup source if the primary is unavailable. Rates refresh every 10 minutes. In the rare event no live source is reachable, the calculator falls back to approximate rates and displays a warning with a retry option.

The tax calculator uses 2024 US federal income tax brackets for the four standard filing statuses: Single, Married Filing Jointly, Married Filing Separately, and Head of Household. It does not account for state taxes, AMT, tax credits, or itemised deductions beyond the figure you enter.

QuickSum results are estimates intended to help you understand and plan. They are not a substitute for professional financial, tax, or medical advice. Before making significant decisions — such as taking out a mortgage or planning retirement — please consult a qualified financial adviser.

For metric units: BMI = weight (kg) ÷ height (m)². For imperial units: BMI = (weight in lbs × 703) ÷ height (in)². These are the standard World Health Organization formulas.

No. All calculations happen entirely inside your browser using JavaScript. The values you type are never sent to any QuickSum server. The only data stored locally is your theme preference (light/dark) and your cookie consent choice.

Yes, minimally. We use local storage to remember your theme and consent preferences, and analytics cookies to understand aggregate site usage so we can improve QuickSum. You can accept or decline non-essential cookies via the banner on your first visit. See our Cookie Policy for full details.

Since QuickSum does not collect personal data, there is nothing to delete on our end. To remove locally stored preferences, clear your browser’s localStorage and cookies for this site (usually under Browser Settings → Privacy & Security → Site Data).

QuickSum works in all modern browsers: Chrome, Firefox, Safari, Edge, and their mobile equivalents. We recommend keeping your browser up to date for the best experience.

Yes. QuickSum is fully responsive and designed to work well on phones, tablets, and desktops. The mobile layout hides the sidebar navigation and replaces it with a hamburger menu.

Use the sun/moon toggle in the top-right corner of any page. QuickSum also automatically matches your operating system’s colour scheme on your first visit.