Maryland's top marginal state income tax rate is 5.75%. State tax is progressive here, so most filers pay an effective rate well below the top figure — the calculator applies a blended approximation rather than modeling the full bracket schedule.
County income tax surcharges stack on top of the state rate. Statewide median household income is $99,000, which is the default loaded above.
Remember that a state with no income tax is not automatically cheaper overall. Maryland has an effective property tax rate of 0.95% and average homeowners insurance of $1,300 a year — states without wage income tax typically recover revenue through property or sales taxes.