Guides on deductions, planning strategies, and IRS rules — written for people who actually pay taxes.
Adjusted Gross Income is the number the IRS uses to calculate almost every deduction, credit, and phase-out. Understanding it is the single most valuable thing you can do before filing.
Pass-through owners can deduct up to 20% of business income — but the SSTB phaseout turns one extra dollar costly. Who qualifies, the 2026 thresholds, and how to plan.
SALT cap status, the bonus depreciation phase-down, Section 179 limits, QBI thresholds, and the TCJA sunset — the legislation-dependent numbers, dated in one place.
Bracket, basis, depreciation, QBI, SALT, MAGI, AMT — every tax term that shows up on a return, defined with examples.
The popular rule of thumb says elect S-Corp once net SE income hits $80k. Count the income tax a salary adds by shrinking the QBI deduction, and the salary you pay yourself decides the answer far more than that number does.
Pass-through entity tax (PTET) elections, charitable bunching, and trust-based shifts — the legal moves that route around the SALT cap (now $40,400 for 2026, phasing down above $505,000 MAGI).
If your 401(k) allows after-tax contributions + in-plan Roth conversion, you can shovel up to $47,500 more into Roth — tax-free growth forever.
Real Estate Professional Status unlocks unlimited rental-loss deductions against W-2 income. The 750-hour test is strict — here's how to actually pass it.
Section 199A lets qualified self-employed filers deduct up to 20% of qualified business income. Most freelancers qualify and never claim it.
CA's top income tax rate is 13.3% — and the effective top rate reaches ~14.6% once the 1.3% SDI payroll surcharge (2026, no longer wage-capped) is included. These four moves legally reduce your CA exposure without leaving the state.
Marginal brackets, deductions, and state-specific moves for all 50 states — pick yours to see the exact rates that apply to your income.
Long-form posts on the strategies that actually move the needle — entity choice, equity comp, retirement layering, state planning.
A contact form that takes a screenshot or PDF, our support email, and the fastest way to reach us when something in the calculator isn't matching your CPA's number.
What data we collect, what we don't, how we protect it, and who can see it. We never sell or share your tax inputs.
The rules of using Deductsy — the legal agreement between you and us.
Deductsy is a tax-planning estimator — not tax advice or a filing tool. Always confirm with a CPA before filing.
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Your total income minus 'above-the-line' deductions (Traditional IRA, HSA, half of SE tax, student loan interest, etc.). AGI is the basis for most deduction phaseouts and credit eligibility.
A deduction taken before AGI is calculated. Includes Traditional IRA, HSA, self-employed health insurance, half of SE tax, student loan interest, educator expenses. You don't need to itemize.
A parallel tax calculation that disallows certain deductions. After the 2017 TCJA raised exemptions, AMT now mostly affects ISO exercises or large pre-SALT-cap state-tax deductions.
A workaround for high earners above the Roth IRA limit. Contribute up to $7,500 to a Traditional IRA, then convert to Roth shortly after. With no other Traditional IRA balances, no tax is owed.
An accelerated depreciation deduction for qualifying business property. 100% and permanent for property acquired after Jan 19, 2025 (OBBBA); the old TCJA phase-down (60% 2024 → 0% 2027) applies only to earlier acquisitions. Most powerful paired with cost segregation.
Tax on profit from selling an investment. Long-term (>1 year): 0% / 15% / 20% based on income, plus 3.8% NIIT above $200,000 single. Short-term: ordinary income rates.
An engineering study that reclassifies parts of a property's basis from 27.5/39-year lives to shorter 5/7/15-year lives. Can accelerate $30k–$80k of deductions into year 1 on a $500k+ property.
$2,200 per qualifying child under 17 (permanent, indexed; $1,700 refundable). Phases out at AGI above $200k single / $400k MFJ by $50 per $1,000 over the threshold.
A retirement plan promising a specific benefit at retirement, with contributions calculated actuarially. Self-employed 45+ owners with stable income can shelter $100k–$300k+/year.
When you sell depreciated property, the IRS recaptures the depreciation you took (or could have taken) at a special 25% rate. Even §121 primary-residence exclusions don't avoid this. 1031 exchanges defer it.
A charitable giving account where you contribute a lump sum (immediate deduction) then distribute over time. Used for the 'bunching' strategy to exceed the standard deduction in a single year.
A refundable credit for low-to-moderate-income workers, especially with kids. For 2026: $664 (no kids) up to $8,231 (3+ kids). Often missed after a temporary income drop.
The combined 15.3% Social Security + Medicare tax. Split 50/50 between employer and employee for W-2 workers. Self-employed pay both halves but deduct half on Schedule 1.
Triple-tax-advantaged account: deductible going in, tax-free growth, tax-free out for medical. 2026 limits: $4,400 self / $8,750 family. Requires a high-deductible health plan.
A list of specific deductions (mortgage interest, SALT, charitable, medical) you can take instead of the standard deduction. Worth itemizing if the total exceeds the standard.
Contribute up to ~$47,500 in after-tax dollars to a 401(k) and convert to Roth, on top of the $24,500 employee limit. Requires your plan to allow both after-tax contributions and in-plan conversions.
An extra 3.8% tax on investment income (dividends, capital gains, rental income, interest) for households with AGI above $200,000 single / $250,000 MFJ. Started in 2013 to fund the ACA.
Limits how rental property losses can offset other income. Two exceptions: the $25k allowance (phased out $100k–$150k AGI), and Real Estate Professional Status (750+ hours).
Roth conversions are treated proportionally across ALL your Traditional IRA balances. This trips up Backdoor Roth — a SEP-IRA or rollover IRA balance makes the conversion mostly taxable.
A 20% deduction on pass-through business income. Made permanent by OBBBA, with a new $400 minimum (2026). Phases out starting ~$201,750 single / ~$403,500 MFJ (2026) for specified service businesses (consulting, law, medicine, finance).
The IRS requires S-Corp owners to pay themselves reasonable compensation for the work they perform. A common (non-binding) heuristic: 40–60% of net business income. Use comp data for documentation.
An IRS designation that makes rental losses non-passive. Requires 750+ hours/year in real property trades AND >50% of total personal-services hours. Heavily audited — keep time logs.
Mandatory withdrawals from Traditional retirement accounts starting at age 73 (raised by SECURE Act 2.0). Roth IRAs have no RMDs; Roth 401(k)s no longer have them as of 2024.
Originally $10,000 per return under the 2017 TCJA; OBBBA raised it to $40,400 (2026), phasing down by 30% of every dollar of MAGI above $505,000, to a $10,000 floor, reverting to $10,000 in 2030. Now mainly binds households above $505,000 MAGI.
A nonrefundable credit up to $1,000 ($2,000 MFJ) for retirement contributions if AGI is under specific thresholds. Often missed by filers who don't realize their retirement contributions also generate this credit.
Lets businesses deduct the full cost of qualifying equipment in the year purchased rather than depreciating. 2026 limit: $2.56M (raised by OBBBA from $1.22M; permanent, indexed). Phases out dollar-for-dollar above $4.09M in equipment purchases.
The 15.3% combined Social Security (12.4% to $184,500) + Medicare (2.9%) tax for self-employed individuals. Half is deductible above-the-line. S-Corp election partially escapes this.
A self-employed retirement plan with employer-only contributions up to ~20% of net SE income. 2026 max: $72,000. Simpler than Solo 401(k); contributions allowed until tax filing deadline + extensions.
A 401(k) for self-employed individuals with no non-spouse employees. Allows both employee ($24,500) and employer (~25% of compensation) contributions, up to a combined $72,000. Most providers offer Roth.
A flat deduction without itemizing. 2026: $16,100 single / $32,200 MFJ / $24,150 HoH. After TCJA roughly doubled standard amounts, only ~10% of filers itemize.
If average guest stay is ≤7 days, the rental isn't passive — losses can offset W-2 or business income WITHOUT REPS. Material participation (100+ hours and more than anyone else) is required.
Selling investments at a loss to offset gains, plus up to $3,000 of ordinary income annually. Excess losses carry forward. Watch the wash-sale rule: no substantially identical security within 30 days.
Your AGI minus the standard deduction or itemized deductions, minus the QBI deduction. This is what federal brackets apply to — different from AGI, which drives most phaseouts.
See how much an S-Corp election could trim from SE tax.
Pass-through entity tax — the SALT cap workaround for owners.
Simplified vs actual-expense method, side by side.
Route after-tax dollars into a Roth IRA, even above the limit.
How much to convert this year without bumping a bracket.
Compare contribution headroom for the self-employed.
State tax break sizing for college savings contributions.
Offset gains by realizing losses before year end.
Equity comp tax math — vesting, AMT, and qualifying dispositions.
Schedule E depreciation, basis, and passive loss limits.
Dial in estimated payments to avoid underpayment penalties.
Pick the deduction path that wins for your numbers.
What Schedule SE costs on your net profit, and the half you deduct.
Your Section 199A deduction, and which limit is reducing it.
How a long-term gain stacks on your income, band by band.
The year's federal brackets, plus your marginal and effective rate.
401(k), IRA and HSA limits, and the room you have left.
Business miles priced per half when the IRS resets mid-year.
Your cap after the MAGI phase-down, and the statutory reversion.
Answer a few questions and see your own 2026 number — what you owe, and every move still open to you before the year closes.
Your number, every move that applies to you, and the date each one closes — saved to your account and tracked all year.