What Deductsy is, and who it is for
Tell it how you earn and it estimates your 2026 federal and state income tax, in all 50 states and the District of Columbia — including self-employment tax, the qualified business income deduction, the net investment income tax, the alternative minimum tax and the passive-loss rules. W-2 income, rental properties and businesses (sole proprietorship, LLC, S-corp or K-1) are combined into one household return rather than estimated separately and added up.
The plan follows the kind of income you have:
- Just a paycheck: Free
- A rental: Plus ($79 a year)
- A business: Pro ($199 a year)
The 19 calculators and the state tax guides are free and need no account. Deductsy does not file your return: it is for deciding what to do while the tax year is still open, and the paid plans export a packet you can hand to whoever prepares it. Compare the plans.
Where the figures come from, and how they stay current
Every federal figure that changes from year to year — the brackets, the standard deduction, contribution limits, phase-out thresholds — is kept in tables keyed by tax year. The tax engine and the app compute from those tables, and the public pages generate the yearly figures they quote most from the same tables.
Current-year figures record the document they came from: an IRS revenue procedure or notice, or the section of the Internal Revenue Code that sets them. The project's automated tests fail if one of the core yearly figures is added without a citation.
When the IRS publishes the next year's figures, usually in the autumn, they are added to the tables, and a published figure always replaces an estimate. Until then, a year without published figures is projected forward from the last published year with an inflation factor, and every page showing those figures says that they are estimates.
A figure the law sets on its own schedule is modelled as the law writes it rather than inflated. The SALT deduction cap is $40,400 for 2026, rises 1% a year through 2029, and reverts to $10,000 in 2030.
State income tax rates come from each state's own statute or revenue department schedule. Each state guide names that source, the tax year the schedule is for and the date it was checked, and says so when a state has not yet published the current year's schedule. Property tax figures are statewide average effective rates from WalletHub's 2026 release of Census American Community Survey data, and vary widely within a state.
The federal figures cited on these pages were last checked against the published documents on .
Sources
- Standard deduction, 2026 — Rev. Proc. 2025-32
- Federal income tax brackets, 2026 — Rev. Proc. 2025-32 §4.01, Tables 1–4
- Long-term capital gains rate brackets, 2026 — Rev. Proc. 2025-32
- Alternative minimum tax exemption and phase-out, 2026 — Rev. Proc. 2025-32; phase-out per OBBBA (Pub. L. 119-21) §70107
- QBI deduction thresholds, 2026 — Rev. Proc. 2025-32
- Section 179 expensing limit, 2026 — Rev. Proc. 2025-32 — §179(b)(5) SUV sub-limit $32,000
- HSA contribution limits, 2026 — Rev. Proc. 2025-19
- IRA and Roth IRA limits, 2026 — IRS Notice 2025-67
- 401(k) employee deferral limit, 2026 — IRS Notice 2025-67 — §402(g)(1)
- Total defined-contribution limit, 2026 — IRS Notice 2025-67 — §415(c)(1)(A)
- SALT deduction cap, 2026 — OBBBA (Pub. L. 119-21), cap and threshold indexed
- Standard mileage rate, 2026 — Notice 2026-10 (Jan–Jun); Announcement 2026-11, IRB 2026-29 (Jul–Dec)
- Medical expense floor, 2026 — §213(a) — statutory 7.5%, not indexed
- Net investment income tax, 2026 — §1411 — statutory thresholds, never indexed
- Additional Medicare tax, 2026 — §3101(b)(2) — statutory thresholds, never indexed
- Social Security wage base, 2026 — SSA annual wage-base announcement ($184,500)
- Underpayment interest rate, by quarter, 2026 — §6621(a)(2), short-term rate + 3 points, reset quarterly — Rev. Rul. 2025-22 (Jan–Mar); Rev. Rul. 2026-5 (Apr–Jun); Rev. Rul. 2026-10 (Jul–Sep); Rev. Rul. 2026-15 (Oct–Dec)
- Charitable deduction floor (0.5% of AGI), 2026 — OBBBA (Pub. L. 119-21) §70425 — §170(b)(1)(I), 0.5% of the contribution base
What the estimates are, and what they leave out
Every result is a planning estimate built from the numbers you enter. The app deliberately does not ask for the details that move the answer only slightly, so it is not your return, and it is not a substitute for one.
Above $500,000 of household income there are more moving parts than it models. These are not modelled, and the app names them where they apply rather than leaving them out quietly:
- Massachusetts' 4% surtax on income over about $1M. It was deliberately left out as above our range, so a Massachusetts return will be understated.
- State alternative minimum tax. Several states run their own AMT that mostly catches large deductions and stock options. We model the federal one only.
- Multi-state and part-year returns. We report what we can't answer rather than guessing, but allocating income between states is common at this level and we don't do it.
- Community property splitting. It changes a married-filing-separately return in nine states, and we don't split income between spouses.
- Incentive stock options and the AMT they trigger. We handle the ordinary side of equity compensation, not a full Form 6251 exercise analysis.
- Our deduction benchmarks. They're planning references built from typical returns in our range, so they compare you against the wrong crowd.
The state guides' tax tables leave out local income taxes.
Editorial policy
- The yearly figures the public pages quote most — the SALT cap, the standard deduction, the 401(k), IRA and HSA limits, the QBI thresholds and the Social Security wage base — are generated from the same tables the tax engine computes with, and an automated check fails if one of them is typed into a public page.
- Pages that quote figures show the tax year they are for, when those figures were last reviewed, and the documents they came from. Guides and posts also show when they were last revised.
- Estimates are labelled. A figure projected ahead of IRS publication is never presented as published, and a state figure taken from an earlier year's schedule is named as such.
- Sources are the primary documents — IRS revenue procedures and notices, the Internal Revenue Code, and each state's statute or revenue department — except where a page names a different source, as the property tax averages do.
- Guides and posts are published under the Deductsy name.
- Some calculators carry affiliate links; how that works is set out in the affiliate disclosure.
- To report an error, use the support page. A corrected figure is changed in its table, and the pages that read it update with it.
Disclaimer
A planning estimate, not tax advice — confirm with a CPA before you file.
The full terms are on the disclaimer page.
Contact
Questions, corrections, or a figure that does not match your preparer's: send a message through the support page.