Real Estate · IRC §121 · Rev. Proc. 2025-32 · TY 2026
Estimate the federal tax on the sale of your primary residence. Applies the IRC section 121 exclusion up to $250,000 (single) or $500,000 (joint), models the section 1250 unrecaptured depreciation gain at 25 percent, and applies the 2026 long-term capital gains rates from Rev. Proc. 2025-32.
Want to understand the ownership and use tests, partial exclusion rules, and how section 1250 depreciation recapture works before you calculate? The Home Sale §121 Exclusion Guide covers the full doctrine.
Read the Guide →If you owned and used your home as your principal residence for at least 2 of the past 5 years, IRC section 121 excludes up to $250,000 of gain (single) or $500,000 (married filing jointly) from federal income tax. Gain above the exclusion limit is taxed as a long-term capital gain at 0, 15, or 20 percent depending on your total income under Rev. Proc. 2025-32, with any section 1250 unrecaptured gain (from prior depreciation) taxed at a maximum 25 percent rate. If the gain is fully excluded, no capital gains tax or net investment income tax applies.
Adjusted basis = purchase price + purchase closing costs + permanent improvements - cumulative depreciation claimed. Improvements include additions, structural upgrades, and major systems replacements. Maintenance and repairs do not increase basis. Depreciation reduces basis by the total amount you claimed (or were allowed to claim) for any rental use or home office deduction.
Amount realized = sale price - selling expenses. Selling expenses include real estate commissions, seller-paid closing costs, title fees, and transfer taxes paid from the sale proceeds.
Realized gain = amount realized - adjusted basis. If the result is negative (a loss), no gain tax applies. A personal-use property loss is not deductible.
If you are fully qualified, the calculator applies the full $250,000 / $500,000 exclusion against realized gain. For partial qualification, the calculator applies the reduced exclusion: max exclusion × (qualifying months / 24). No exclusion is applied if you are not qualified.
If you entered prior depreciation, the calculator identifies the section 1250 unrecaptured gain as the lesser of: (1) total depreciation claimed, or (2) the taxable gain after exclusion. This portion is taxed at a maximum 25% federal rate.
The remaining taxable gain (after the §1250 portion) is taxed at the applicable LTCG rate. The calculator stacks your ordinary income below the gain, then applies the 0/15/20% thresholds from Rev. Proc. 2025-32 to the LTCG portion. To model that 0/15/20% stacking on its own for any gain or qualified dividend, use the Qualified Dividends and Capital Gains Tax Calculator.
The calculator estimates NIIT at 3.8% on the lesser of: (1) the total non-excluded taxable gain, or (2) the amount by which your estimated AGI (other income + taxable gain) exceeds the NIIT threshold ($200,000 single / $250,000 MFJ). Gain that is fully excluded under §121 is not subject to NIIT.
In this example, the entire $385,000 gain is excluded. Federal capital gains tax = $0. NIIT = $0 (excluded gain is not subject to NIIT).
Now suppose the couple had a $650,000 gain instead. The exclusion covers $500,000. The remaining $150,000 is taxed as a long-term capital gain. With other income of $120,000 (MFJ, 2026), taxable ordinary income is $120,000 - $32,200 standard deduction = $87,800. The $150,000 LTCG stacks on top. The 15% LTCG bracket runs to $613,700 MFJ; $87,800 ordinary income leaves $525,900 of 15% LTCG room remaining. The full $150,000 LTCG falls within the 15% bracket. LTCG tax = $22,500. NIIT: AGI = $120,000 + $150,000 = $270,000. NIIT threshold MFJ = $250,000. NIIT applies to lesser of $150,000 gain or $20,000 excess over threshold = $20,000 × 3.8% = $760. Total federal tax on the home sale: approximately $23,260.
The two most overlooked basis items are purchase-closing-cost additions and prior depreciation reductions. Buyers rarely keep their HUD-1 or settlement statement from the original purchase, so when they sell 10 years later they understate their basis and overstate their gain by $8,000 to $20,000 in typical transactions. Pull the original closing disclosure before calculating. On the depreciation side: if you ever deducted a home office or rented a room for any period, IRS records show the depreciation allowed even if you stopped claiming it. The amount allowed (not just claimed) reduces basis. This catches taxpayers who "forgot" about a home office from 2016 to 2020 and then sell in 2026 assuming zero depreciation.
James bought a duplex in 2019, lived in one unit, and rented the other. He claimed $18,000 of depreciation on the rental unit over 6 years. He sold in 2026 for a $320,000 total gain.
The rental portion has its own rules. For the unit James occupied, he may qualify for the §121 exclusion on that portion (the personal-use share of the gain). For the rental unit, no §121 exclusion applies, and the $18,000 of prior depreciation is unrecaptured §1250 gain, taxed at his ordinary rate up to a 25% ceiling. The remaining rental gain is taxed as LTCG. James files as single, with $85,000 of other ordinary income, so his 2026 taxable ordinary income is $68,900 after the $16,100 standard deduction and the $18,000 falls entirely in the 22% bracket. His §1250 tax: $18,000 × 22% = $3,960. His remaining rental LTCG falls in the 15% bracket. The personal-use gain is fully excluded.
The split-use scenario is significantly more complex than a pure primary residence sale and typically requires a professional cost-basis allocation worksheet. This calculator handles the simplified case where the entire property was used as a primary residence.
| Rate | Single / HOH top taxable income | MFJ top taxable income |
|---|---|---|
| 0% | $49,450 (single) / $66,200 (HOH) | $98,900 |
| 15% | $545,500 (single) / $579,600 (HOH) | $613,700 |
| 20% | above $545,500 (single) | above $613,700 |
| 25% max | Section 1250 unrecaptured gain (prior depreciation) - all income levels | Section 1250 unrecaptured gain - all income levels |
| +3.8% NIIT | Single/HOH: AGI above $200,000 (not inflation-adjusted) | MFJ: AGI above $250,000 |
Source: IRS Rev. Proc. 2025-32 (LTCG brackets). IRC §1411 (NIIT thresholds - not inflation-adjusted). IRC §1(h)(1)(D) (§1250 max 25%).
Correction · October 2026. An earlier version of this calculator excluded depreciation-related gain under section 121, ignored unused standard deduction, and taxed unrecaptured section 1250 gain at a flat 25%. IRC §121(d)(6) bars excluding that gain, and the Schedule D Tax Worksheet taxes it at ordinary rates capped at 25%. Results changed, and the James example now shows $3,960 instead of $4,500. See our Corrections Policy and Log.
Your home was your sole primary residence for the full ownership period. No rental use, no home office, no periods of non-primary use. The gain is clearly under the exclusion limit ($250K single / $500K MFJ). You received no Form 1099-S, or you did receive one and the gain is fully excluded. File the sale on Form 8949 with the §121 exclusion noted.
Your gain exceeds or approaches the exclusion limit and the taxable portion could push you into the 20% LTCG rate or trigger NIIT. You claimed a home office deduction for any year. You rented any portion of the property at any point. You are selling a home received as a gift or inheritance. You have a complex ownership history (divorce, death of spouse, IRA-owned property, or trust ownership). You are using installment sale treatment. The §121 exclusion planning, §1250 recapture, and mixed-use allocation are all areas where professional cost-basis reconstruction commonly recovers far more than the professional's fee.
If you are selling a rental property: use the Rental Income Tax Calculator to model your §1250 recapture and LTCG treatment on investment property. If you are evaluating whether to itemize selling costs: use the Itemize vs. Standard Deduction Calculator. To model your overall 2026 filing status impact: use the Filing Status Calculator.
Disclaimer: This calculator provides federal tax estimates for educational purposes only. It does not constitute tax advice. Results assume a pure primary residence with no mixed-use allocation. Tax law is complex and individual circumstances vary. Consult a qualified tax professional or CPA before making decisions based on these estimates. National Tax Tools is not a tax advisory firm.