Yes, all tax calculators provided by the Inland Revenue Authority of Singapore (IRAS), Singapore's tax authority, are completely free to use. There is no sign-up or payment involved.
IRAS publishes a range of free calculators covering income tax, corporate tax, GST, property tax, stamp duty and withholding tax. You can access them all on the IRAS website under Quick Links → Calculators (iras.gov.sg/quick-links/calculators), or through the links on our own calculator pages, which direct you to the relevant IRAS tool.
Do note that these calculators give an estimate for guidance only and may not capture every relief, incentive or adjustment. If you would like a precise computation or advice tailored to your circumstances, Apexia offers full tax and accounting services and is happy to help.