What is the Massachusetts income tax rate?

Massachusetts taxes most income at a flat 5% rate. Since 2023 a voter-approved 4% surtax also applies to taxable income above $1,000,000, so high earners face a 9% marginal rate on income over that threshold.

How does the Massachusetts millionaire surtax work?

The 4% surtax applies only to the portion of taxable income above $1,000,000, not your whole income. For example, $1.2M of income owes 5% on the first $1M and 9% (5% + 4%) on the remaining $200,000.

Is short-term capital gains taxed differently in MA?

Yes. Massachusetts taxes short-term capital gains at 8.5% rather than 5%. This calculator models the standard 5% earned-income rate plus the surtax and does not separately compute short-term gains.

Does Massachusetts have local income taxes?

No. Massachusetts cities and towns do not levy a separate income tax, so the 5% state rate (plus any surtax) is the only income tax on your wages.

Is my income data sent anywhere?

No. The calculation runs entirely in your browser. Nothing you enter is uploaded or stored.

Massachusetts Income Tax Calculator

Massachusetts taxes most personal income at a flat 5%. Since 2023, a voter-approved 4% surtax (the “millionaire surtax”) also applies to taxable income above $1,000,000, pushing the top marginal rate to 9%. This free calculator applies both correctly.

How it works

The Massachusetts tax formula in this tool is:

Apply 5% to your full Massachusetts taxable income.
If income exceeds $1,000,000, add a 4% surtax on the portion above $1M only — not on the whole amount.
Sum the two to get your total Massachusetts income tax.

Because the surtax is marginal, only the dollars above the $1M line ever face the extra 4%.

Example

Someone with $1,200,000 of taxable income pays 5% × $1,200,000 = $60,000 in base tax, plus 4% × ($1,200,000 − $1,000,000) = $8,000 of surtax, for $68,000 total. The effective rate is about 5.67% even though the top marginal rate is 9%.

Notes

This estimate covers Massachusetts state income tax only — not FICA, federal tax, or the separate 8.5% short-term capital-gains rate. Massachusetts has no local income tax. The $1M surtax threshold is indexed for inflation and may rise slightly each year.