Disclaimer

General information only

Everything on PercentBase — the calculators, the formulas, the worked examples and the written explanations — is provided for general informational and educational purposes. It is arithmetic and explanation, nothing more.

Not financial or tax advice

The discount, tip, markup, tax and reverse percentage calculators perform the arithmetic you ask of them using the figures you supply. They do not know your country, your tax jurisdiction, your business structure or your circumstances, and they make no judgement about which rate applies to you.

Tax rules in particular vary by country, by state or province, by product category, and over time. Nothing on this site should be treated as advice on what rate to charge or pay. Consult a qualified accountant or your local tax authority for anything that matters.

Not academic or professional advice

The grade calculator applies a standard weighted-average method. Individual institutions use their own rules for weighting, rounding and grade boundaries, and those rules take precedence over anything calculated here. Always check your official course documentation and your institution's published grading policy.

Accuracy and verification

Every formula on this site is covered by an automated test suite run against the live calculator code, and results include the working so you can follow the method yourself. We still cannot guarantee that results are error-free in every possible case, and we do not accept responsibility for decisions made solely on the basis of a result shown here.

Please verify any figure that matters — anything involving money, contracts, grades or deadlines — before acting on it.

Rounding

Results are rounded for display: money to two decimal places, percentages to four, general numbers to six. Rounding means a displayed figure may differ very slightly from one produced by a system carrying more decimal places, which matters most when many calculated values are summed.

External links and advertising

This site links to external websites and carries third-party advertising. We do not control that content and are not responsible for it. The presence of an advertisement is not an endorsement.

No guarantees of availability

We aim to keep the site running and correct, but it is provided without any warranty of availability, fitness for a particular purpose or freedom from error.

Reporting a problem

If you believe a calculator is producing an incorrect result, please tell us at hello@percentbase.com. Include the calculator, your inputs and the answer you expected — or simply press Copy link under the result and paste that link into your message.