Effective rate measures the overall tax burden on your income. It blends every bracket your income has crossed, weighted by how much income fell into each. Because lower slices are taxed lightly, the effective rate is typically 8–15 percentage points lower than the marginal rate.
Use the effective rate to compare countries or to budget — it tells you what share of gross income actually goes to tax. Use the marginal rate for decisions at the margin (overtime, deductions, additional freelance work).
Public commentary often confuses the two. A French earner at EUR 50,000 has a 30% marginal rate but only a 16% effective rate. Mixing them up overstates the burden of moderate incomes and understates it for very high earners.
Effective tax rate = Total tax / Total taxable income
A German earner with EUR 60,000 taxable income who pays EUR 13,200 in tax has an effective rate of 22%, even though their marginal bracket is 42%.