This uses an editable overall deduction rate you enter yourself, because UK, US and Canadian tax bands differ and change. Do not treat the default as your country's official rate — check HMRC, IRS or CRA bands for your situation, or enter the rate from your last payslip.
Gross £4,000 a month at an editable 20% deduction rate: take-home £3,200 a month, deductions £800, yearly take-home £38,400. Change the rate to match your own payslip for a more realistic figure.
Results are estimates for information only, not tax advice. Tax bands, allowances and social charges differ by country and change over time — check the official source for your country.