Tax-Loss Harvesting: Offset Capital Gains and Reduce Taxable Income
Use this guide to understand the assumptions, inputs, results, and next steps behind the calculator.
Tax-loss harvesting turns investment losses into a tangible financial asset by using them to offset realized capital gains and up to $3,000 of ordinary income per year. For investors managing taxable brokerage accounts, strategically selling underperforming assets can significantly lower your annual tax bill while keeping your overall portfolio aligned with your long-term goals. This calculator estimates your potential federal and state tax savings by applying the IRS netting rules to your current realized gains, realized losses, and prior-year carryforwards.
By optimizing how and when you realize losses, you can improve your after-tax returns. This strategy is particularly valuable during market corrections or when rebalancing a portfolio. Lowering your Adjusted Gross Income (AGI) through capital losses can also have secondary benefits, such as reducing your exposure to Medicare IRMAA surcharges or keeping you in a lower bracket for tax-efficient retirement withdrawals.
2026 Capital Loss Deduction Rules and Limits
The IRS dictates exactly how investment losses can be used to offset income. These rules dictate the maximum immediate tax benefit you can receive in a single tax year and how unused losses carry forward into the future.
| Tax Rule | 2026 Limit / Requirement | Strategic Impact |
|---|---|---|
| Ordinary Income Deduction | Up to $3,000 per year ($1,500 if married filing separately) | After offsetting all capital gains, you can use remaining losses to reduce your regular taxable income. |
| Carryforward Limit | Unlimited | Any net losses exceeding the $3,000 ordinary income limit roll over to future tax years indefinitely. |
| Wash Sale Rule | 30 days before or after the sale | If you buy a "substantially identical" asset within this 61-day window, the loss is disallowed for current-year tax purposes. |
| Account Eligibility | Taxable brokerage accounts only | Losses inside tax-advantaged accounts like IRAs or 401(k)s cannot be harvested for tax deductions. |
Why the $3,000 Limit Matters
The $3,000 ordinary income deduction limit has not been adjusted for inflation in decades, but it remains a highly valuable tax shield. Because ordinary income is typically taxed at a higher rate than long-term capital gains, using losses to offset your salary, interest income, or retirement drawdown distributions yields a higher dollar-for-dollar tax savings than offsetting long-term gains.
The IRS Netting Process: How Losses Offset Gains
You cannot simply choose which gains your losses will offset. The IRS requires a specific "order of operations" known as the netting process. The calculator automatically follows these steps to determine your exact tax liability and carryforward amount.
Step 1: Like Offsets Like
First, short-term losses (from assets held one year or less) must be used to offset short-term gains. Simultaneously, long-term losses (from assets held more than one year) must be used to offset long-term gains.
This initial step is crucial because short-term gains are taxed at your higher ordinary income tax rate, while long-term gains enjoy preferential tax rates (0%, 15%, or 20%).
Step 2: Cross-Netting
If you have a net loss in one category and a net gain in the other, they cross over.
- Net short-term losses can offset remaining long-term gains.
- Net long-term losses can offset remaining short-term gains.
Step 3: Ordinary Income Deduction
If you still have a net capital loss after all gains have been offset, you can deduct up to $3,000 against your ordinary income. If your remaining loss consists of both short-term and long-term losses, the IRS requires you to use the short-term losses first to claim the $3,000 deduction.
Step 4: Carryforwards
Any remaining losses beyond the $3,000 ordinary income deduction become a capital loss carryforward. These retain their original character (short-term or long-term) and can be used in future years. Tracking these carryforwards is a vital part of how to withdraw from retirement accounts tax-efficiently.
The Math Behind Your Tax Savings
The calculator applies the IRS netting rules to determine exactly how your losses are utilized and translates that into estimated dollar savings based on your tax brackets.
For the initial loss availability, the calculator applies this formula:
total short-term losses = current short-term losses + prior year short-term carryforward
total long-term losses = current long-term losses + prior year long-term carryforward
Where:
- current short-term losses = Losses realized this year on assets held 365 days or less.
- prior year short-term carryforward = Unused short-term losses rolled over from previous tax returns.
- current long-term losses = Losses realized this year on assets held more than 365 days.
- prior year long-term carryforward = Unused long-term losses rolled over from previous tax returns.
To calculate your estimated federal tax savings, the calculator uses this formula:
federal tax savings = (short-term offset × ordinary tax rate) + (long-term offset × long-term capital gains rate) + (ordinary income deduction × ordinary tax rate)
Where:
- short-term offset = The amount of loss successfully used to cancel out short-term capital gains.
- ordinary tax rate = Your top federal marginal tax bracket (used for both short-term gains and ordinary income).
- long-term offset = The amount of loss successfully used to cancel out long-term capital gains.
- long-term capital gains rate = Your preferential federal rate (usually 15% or 20%).
- ordinary income deduction = Up to $3,000 of excess net loss applied against your regular income.
For state taxes, the calculator assumes your state taxes all capital gains and ordinary income at the same flat rate, applying this formula:
state tax savings = (total gains offset + ordinary income deduction) × state income tax rate
Scenario: Harvesting Losses During a Market Correction
Consider an investor, David, who is reviewing his taxable brokerage account in late 2026. He is in the 24% federal tax bracket, faces a 5% state income tax, and his long-term capital gains rate is 15%.
David has the following realized activity for the year:
- Short-term capital gains: $2,000 (from a quick swing trade)
- Long-term capital gains: $0
- Short-term capital losses: $10,000 (from selling an underperforming tech ETF)
- Long-term capital losses: $0
How the Netting Process Works for David:
- David's $10,000 short-term loss first offsets his $2,000 short-term gain. This saves him from paying 29% total tax (24% federal + 5% state) on that $2,000 gain, yielding $580 in tax savings.
- He now has an $8,000 net short-term capital loss.
- He applies the maximum $3,000 against his ordinary income. This saves him 29% on $3,000 of his salary, yielding $870 in tax savings.
- The remaining $5,000 becomes a short-term capital loss carryforward for next year.
In total, David generated $1,450 in immediate tax savings while preserving a $5,000 tax asset for future years. This strategy is far more tax-efficient than simply holding the losing position and paying taxes on the $2,000 gain.
How Tax-Loss Harvesting Impacts Retirement Planning
For retirees, tax-loss harvesting takes on a different dimension. When you transition from saving to spending, managing your taxable income becomes a delicate balancing act to avoid triggering higher Medicare premiums or increasing the taxability of your Social Security benefits.
If you are taking distributions from a taxable brokerage account to fund your lifestyle, you will likely generate capital gains. By intentionally selling some positions at a loss, you can offset those gains, allowing you to generate tax-free cash flow.
Furthermore, if you are executing a Roth conversion strategy, using harvested losses to claim the $3,000 ordinary income deduction can slightly lower your AGI, potentially giving you more room to convert funds at a favorable tax rate. You can model the impact of these conversions using a Roth IRA tax calculator or by evaluating your Roth IRA MAGI limits.
Frequently Asked Questions
Quick answers to the questions people usually have after running the retirement calculator.
1What is tax-loss harvesting?
Tax-loss harvesting is the strategy of selling taxable investment assets at a loss to offset realized capital gains and reduce your overall taxable income. It is a proactive portfolio management technique used to minimize tax liabilities.
2Can I use capital losses in an IRA or 401(k)?
No. Tax-loss harvesting only applies to taxable brokerage accounts. Because investments inside an IRA, Roth IRA, or 401(k) grow tax-deferred or tax-free, the IRS does not allow you to claim deductions for investment losses sustained within those accounts.
3Does the wash sale rule apply to cryptocurrency?
As of early 2026, the IRS treats cryptocurrency as property, meaning traditional wash sale rules do not currently apply to digital assets like Bitcoin. However, Congress has repeatedly proposed legislation to close this loophole, so investors should verify current IRS guidelines before harvesting crypto losses.
4Are short-term or long-term losses more valuable?
Short-term losses are generally more valuable because they first offset short-term gains, which are taxed at your higher ordinary income tax rate. Long-term losses first offset long-term gains, which are taxed at lower preferential rates (0%, 15%, or 20%).
5What happens if I forget to report a capital loss carryforward?
If you fail to report a capital loss carryforward on your tax return, you may lose the ability to use it in future years unless you file an amended return (Form 1040-X) for the year the loss was generated. Proper tracking is essential.
6Is tax-loss harvesting better than a buy-and-hold strategy?
They are not mutually exclusive. You can maintain a buy-and-hold philosophy while still harvesting losses by immediately reinvesting the proceeds into a similar (but not identical) asset. This allows you to stay fully invested while capturing the tax benefit. You can compare different investment timing strategies using a dollar-cost averaging vs lump sum calculator.
7Can harvested losses offset RMD income?
Yes, up to the $3,000 ordinary income limit. Required Minimum Distributions (RMDs) are taxed as ordinary income. While capital losses cannot directly offset the entirety of a large RMD, the $3,000 deduction will lower your overall Adjusted Gross Income. To learn more, read how to reduce taxes on required minimum distributions.
8Do inherited assets qualify for tax-loss harvesting?
When you inherit an asset, it typically receives a "step-up" in basis to its market value on the date of the original owner's death. You can only harvest a loss if the asset declines in value after you inherit it and you sell it in a taxable account. Complexities surrounding inherited accounts are best modeled with an inherited IRA tax calculator.
Next Steps in Tax Planning
Tax-loss harvesting is just one component of a broader tax-efficient wealth strategy. To continue optimizing your financial plan, consider exploring how to calculate your RMD step-by-step to anticipate future taxable income spikes. If you are approaching retirement, use the how long will my money last calculator to see how reducing your tax drag can extend the lifespan of your portfolio, and review RMD strategies to minimize the tax hit for your pre-tax accounts.