Investment tax · 2026 gain and loss rules
Capital Gains Tax Calculator for 2026
Estimate a gain or loss after basis, selling costs, and other capital losses. For a gain, see long-term band stacking or short-term ordinary tax. For a net loss, see the potential current-year deduction and carryforward.
Quick estimate
Estimate capital gain or loss
Estimated tax on the net capital gain
$14,30724.2% of net taxable gain0% long-term band
$015% long-term band
$59,00020% long-term band
$0For a net loss, the federal planning model applies the $3,000 annual deduction limit ($1,500 if married filing separately) and carries the remainder forward. Actual Schedule D ordering, short- versus long-term netting, taxable-income limits, wash sales, state conformity, and future gains can change the usable deduction and carryforward. Gain estimates exclude asset-specific exemptions, local tax, collectibles, unrecaptured Section 1250 gain, QSBS, and state-specific basis adjustments.
01
How this calculator works
Tax applies to gain, not sale proceeds. The model subtracts cost basis and selling costs to find the transaction’s gain or loss, then nets the other eligible capital losses entered by the user.
When total losses exceed total gains
Capital losses first offset capital gains. If the modeled result remains a net loss, this calculator applies the federal annual ordinary-income deduction limit of $3,000, or $1,500 for married filing separately, and shows the unused amount as a planning carryforward. Actual Schedule D short-term and long-term netting, taxable-income limits, wash sales, and prior carryovers can change the amount used this year.
Long-term gains stack on other taxable income
For 2026, the 0% band ends at $49,450 for single and MFS, $98,900 for MFJ, and $66,200 for head of household. The 15% band ends at $545,500 for single filers, $306,850 for married filing separately, $613,700 for MFJ, and $579,600 for head of household. Other taxable income fills the bands first; only the remaining room is available to the gain.
Short-term gain uses ordinary rates
Property held one year or less generally produces short-term gain. The calculator compares 2026 ordinary tax before and after adding that gain, which is more accurate than multiplying by a single marginal rate when gain crosses brackets.
Incremental Net Investment Income Tax
NIIT is 3.8% of the lesser of net investment income or MAGI above $200,000 for single/HOH, $250,000 for MFJ, or $125,000 for MFS. This model calculates only the additional NIIT attributable to the entered transaction.
Reinvested distributions, commissions, stock splits, inherited or gifted property, wash sales, depreciation, and prior adjustments can change basis. Reconcile tax lots before relying on the estimate.
02
Worked example
A single filer has $40,000 of other taxable income and a $600,000 long-term gain. The first $9,450 fills the remaining 0% band, $496,050 fills the 15% band, and $94,500 falls in the 20% band.
Regular federal capital-gain tax is $93,307.50 before NIIT or state tax. This stacking is why applying 15% to an entire gain can be wrong.
03
Questions people ask
What is the capital gains tax rate in 2026?
Long-term rates are generally 0%, 15%, or 20% depending on taxable income and filing status. Short-term gains generally use ordinary income-tax rates.
Do capital losses reduce capital gains?
Capital losses generally offset gains. If losses exceed gains, the annual ordinary-income deduction is generally limited to $3,000, or $1,500 for MFS, with the remainder carried forward subject to the Schedule D rules.
What happens to a $10,000 net capital loss?
For a filer other than MFS, this planning model shows a potential $3,000 current-year deduction against ordinary income and a $7,000 carryforward. The actual amount can differ when the Schedule D carryover worksheet or taxable-income limit applies.
Does this include the 3.8% NIIT?
Yes, as an incremental estimate based on entered MAGI and other net investment income. Form 8960 contains additional definitions and adjustments.
What counts as cost basis?
Basis often begins with purchase cost and acquisition fees, then changes for events such as reinvestment, splits, return of capital, wash sales, gifts, inheritance, and depreciation.
Does selling a home use these same rules?
Main-home sales can qualify for a separate Section 121 exclusion and have special basis, selling-cost, nonqualified-use, and depreciation rules. Use the home-sale proceeds calculator.
04
Sources and model basis
This calculator is for tax year 2026 — the return filed in early 2027. Rates, brackets, deductions and limits are the ones in force for 2026, including changes enacted during 2026 that apply retroactively to the whole year. It does not estimate any other year.
Published rules and formulas are linked below. Values supplied by the visitor remain scenario inputs, not factual claims.
- IRS Revenue Procedure 2025-32Official 2026 maximum 0% and 15% capital-gain band amounts
- IRS Topic 409: Capital gains and lossesHolding period, loss limits, reporting, and NIIT overview
- IRS Publication 550Investment income, capital transactions, loss deductions, carryovers, and NIIT
- IRS Instructions for Form 8960Net Investment Income Tax definitions and thresholds
- Washington Department of Revenue: Capital gains taxOfficial Washington rules and published deduction years; the unconfirmed 2026 amount is not estimated