Support
Something look off? Tell us.
Help for the calculator on this website and for the Tax.cal app in ChatGPT. Both use the same tax engine and the same rules, so a figure should match wherever you see it.
A wrong figure, a broken page, an outdated rule
Open an issue on GitHub. The most useful report includes:
- the country, region and tax year
- the rule version and last verified date shown with the result (for example IN-2026-27-v1)
- the figure you expected and where it comes from, ideally an official calculator or the law
GitHub issues are public, so use a round example salary rather than your own. For anything private, use the contact details in the privacy policy. Tax.cal is run by Siddhesh Dharamveer Thapa.
Common questions
What does Tax.cal cover?
Tax on a salary for one person in the UK (England, Wales and Northern Ireland), the US (federal tax and every state), Canada (every province), Australia, Ireland, Germany, France, the Netherlands, Spain, Italy and India. It covers income tax, social contributions and state, provincial or regional tax, plus an estimate of the VAT, GST or sales tax inside your spending. It does not cover business or freelance income, capital gains, investment or foreign income, or companies.
How accurate is it?
Direct taxes are calculated from each country's published rates and thresholds for the stated tax year, and each part comes with a confidence level. The tax inside spending is always an estimate, because it depends on what you buy. Treat every result as an estimate and check important decisions with the tax authority or a professional. The terms explain this.
Do I need to give my filing status or state?
In the US, yes: your filing status and your state change the tax a lot, and so does your province in Canada. If you leave one out, ChatGPT may ask you, or it may assume one and say so. Check which one it used, and give your own for an accurate figure. Smaller defaults, such as India's new regime or a typical spending profile, are used and reported with the result.
India: what is "Tax Year 2026-27", and how is it different from AY 2026-27?
From 1 April 2026 the Income-tax Act, 2025 replaces the "previous year" and "assessment year" pair with a single tax year. Tax Year 2026-27 is income from 1 April 2026 to 31 March 2027. AY 2026-27 is the old-law assessment of income earned in FY 2025-26. Tax.cal supports both. For a salaried person, the slabs, rebate and cess are the same in both.
Does Tax.cal store my salary?
Not from the calculator, which runs entirely in your browser, and not from the ChatGPT app, which sends your figures to our calculation service only to work out the answer and does not keep or log them. Tax.cal Plus stores your answers only if you press Save. The privacy policy has the details.
Can Tax.cal file my return or pay my tax?
No. Tax.cal only calculates and explains. Use your tax authority's official service, such as GOV.UK, the IRS or India's e-filing portal, or a professional.