Methodology and sources
A tax calculator is only useful if the numbers can be checked. This page explains where every rate comes from, how the calculation is implemented, and how you can tell when a page was last reviewed.
Where the rates come from
Each calculator is built from the primary published source for that country: the Finance Act or FBR publication for Pakistan, the Income Tax Department and Union Budget for India, GOV.UK and the Scottish Government for the UK, IRS Revenue Procedures for the United States, and the State Taxation Administration for China. The exact link is listed on the country page and in the table below.
| Country | Current tax year | Primary source | Last reviewed |
|---|---|---|---|
| Pakistan | 2026-27 | FBR — Federal Board of Revenue | 1 November 2026 |
| India | FY 2026-27 | Income Tax Department of India | 1 November 2026 |
| United Kingdom | 2026-27 | GOV.UK — Income Tax rates and allowances | 1 November 2026 |
| United States | 2026 | IRS — Revenue Procedure 2025-32 | 1 November 2026 |
| China | 2026 | State Taxation Administration | 1 November 2026 |
Tax years covered
Each calculator opens on the latest published tax year and keeps earlier years available for comparison. The table lists what is currently in the data set.
| Country | Latest year | Earlier years |
|---|---|---|
| Pakistan | 2026-27 | 2025-26, 2024-25, 2023-24, 2022-23 |
| India | FY 2026-27 | FY 2025-26, FY 2024-25 |
| United Kingdom | 2026-27 | 2025-26, 2024-25 |
| United States | 2026 | 2025, 2024 |
| China | 2026 | 2025, 2024 |
Exchange rates
The same-salary comparison converts salaries using rates aggregated by the fawazahmed0 currency-api project, with open.er-api.com as a fallback. Rates are cached for one hour and the date in use is shown on the tool. Conversion never changes the tax rules: tax is calculated in each country’s own currency and converted afterwards for comparison.
How the calculation is implemented
Income tax is progressive, so the calculator splits taxable income into bands and taxes only the part inside each band. The top rate applies to the last slice of income, not to the whole salary. That is why the effective rate is always lower than the marginal rate.
- Taxable income is gross salary minus the deductions the country allows.
- Bands are applied in order, from the lowest threshold upwards.
- Surcharges, cesses, payroll taxes and social contributions are added after income tax.
- Reliefs such as India’s Section 87A rebate are applied before cess and surcharge.
- Figures are shown rounded to whole currency units; the calculation itself keeps full precision.
The formulas used
- Income tax
- Sum of (income inside each band × that band’s rate), plus surcharge and cess where they apply.
- Effective tax rate
- Income tax ÷ gross salary × 100.
- Take-home pay
- Gross − income tax − employee contributions. Contributions include social insurance and housing fund (China), National Insurance (UK), FICA (US) and any pension or 401(k) selected in the options.
- Why the columns do not always add up
- UK National Insurance and US FICA appear inside the tax line. China’s social insurance and housing fund are separate deductions, so gross − tax leaves a larger figure than take-home. The deductions column shows the difference.
Automated checks
The calculation engine has an automated test suite that runs on every change. It checks each country against a published worked example or a hand-calculated figure, and a second suite validates the data itself: every band list must be strictly increasing and end at infinity, every current year must be the newest year available, and each headline rate and threshold is asserted against the official table.
For example, a 15 lakh salary in India under the new regime must produce 97,500 of tax, a 60,000 US salary must produce 5,020 of federal tax and 4,590 of FICA, and the fixed tax at each Pakistani band start must match the Finance Act 2026 amounts (116,000, 541,000, 976,000 and 1,424,000). A further check asserts that gross − tax − deductions equals take-home for every country. If a rate change breaks one of those checks, the build fails before it reaches the site.
What the calculators do not cover
The estimates model salary income only. They do not include self-employment, rental income, capital gains, investment income, state or local taxes, credits, or every deduction available in each country. Each calculator lists its inclusions and exclusions directly under the result, and the country pages repeat them in full.
Corrections
If a rate looks wrong, email support@taxgloby.com with the country, tax year, the salary you entered and the figure you expected. Corrections that can be traced to an official source are normally published within a few days, and the review date on the page is updated.
Independence
Tax Globy is independent and is not affiliated with any tax authority. The calculators are informational tools, not advice, and they do not file returns.