What Is the Marginal Tax Rate?
Definition
Marginal Tax Rate: The rate of the highest tax bracket the taxable income reaches. It shows the tax on one more unit of income; it does not apply to the whole income.
The marginal tax rate is the rate of the highest tax bracket the taxable income reaches. It shows how much tax one more unit of income carries. It does not apply to the whole income: lower brackets keep their own rates. It rises step by step as the taxable income crosses each bracket limit.
Where it appears in the formulas
The marginal rate is read from the tariff rather than computed: marginal rate = rate of the bracket the taxable income falls in. The income tax calculator shows it as a separate result.
The difference from the average rate
The average (effective) tax rate is the total tax divided by the taxable income. Under a progressive tariff it is never above the marginal rate.
In Türkiye
In the 2026 tariff the marginal rate can be 15%, 20%, 27%, 35% or 40%. For non-wage income in 2026, a taxable income between 1,000,000 and 5,300,000 TRY has a marginal rate of 35%.