Index card · Taxes
Federal income tax and bracket calculators
A 1040 estimate and a marginal-rate calculator on 2026 brackets and standard deductions (Rev. Proc. 2025-32)2026 · IRS Rev. Proc. 2025-32: the two tools clients use to ask 'what will I owe?' and 'what does one more dollar cost me?'
These are the most searched tax questions of the season. The 1040 calculator estimates total federal tax from income, filing status and deductions; the marginal rate calculator shows the bracket the next dollar falls in, which is the number most planning decisions turn on.
When clients look up their bracket
1040 Federal Income Tax
February, when the W-2s and 1099s are in. “how much federal tax will I owe this year”
Marginal Tax Rate
December, when a bonus or a year-end move is on the table. “what tax bracket am I in and what happens if I earn more”
Income tax & brackets: questions firms ask
What is the difference between the 1040 and marginal rate calculators?
The 1040 calculator estimates total federal tax and the effective rate. The marginal rate calculator focuses on the rate applied to the next dollar of income, which is what matters for a bonus, a Roth conversion or a deduction.
Do they include the SALT cap?
The 1040 calculator applies the state and local tax cap as the 2026 law sets it, $40,4002026 · Federal law in the calculator's assumptions.
Do they model AMT or capital gains rates?
No. Both say so in their limits. Clients with significant capital gains or AMT exposure need a professional projection, which is a good reason for the request.
Which filing statuses are supported?
Single, married filing jointly, married filing separately and head of household.
Can a client compare two scenarios?
They can run the calculator twice, for example with and without a bonus. Firms often use the marginal rate result to explain why a deduction is worth less than the client expected.
Are state taxes included?
No, federal only. Each calculator page states this, and firms can add a line in the button text about state returns.
Who should put these calculators first on a site?
Tax preparers and CPA firms with individual clients, from February through mid-April.
Which plan includes them?
Network, as part of the tax topic. See pricing.
No question matches that filter. Clear it to see them all, search the whole site, or ask us directly; we reply within one business day.
Next entry
Answer 'what will I owe?' on your own site
Embed both federal income tax calculators and receive the client's income and filing status with every request.
Firm and Network plans include a 14-day trial. Cancel before it ends and you pay nothing.