Is this the exact amount I will receive in payroll?
No. This is an estimate for planning. Payroll basis, credits applied, pension setup, and taxable benefits can change the real outcome.
Why can two people on the same salary see different take-home pay?
Credits, USC/PRSI reliefs, pension arrangements, benefit-in-kind, and payroll timing can all change the result.
Why can a small change near €50,000 look bigger or smaller than expected?
Near band or threshold boundaries, a portion of income can switch between different rates. That can change the marginal deduction on the next euro, even if total income only changes slightly.