Tax Loss Harvesting Calculator

Use this calculator to plan tax-loss harvesting before year-end. Enter the gains and losses you have already realized this year, any capital loss carryforward from prior years, your unrealized losses, your filing status, and your tax rates. The calculator shows how much loss you need to harvest to wipe out this year's net gains and use the full ordinary-income deduction, what that saves in tax, and how much would carry forward if you harvested everything.

Short answer: capital losses first offset capital gains, then up to $3,000 of ordinary income ($1,500 if married filing separately), and anything left carries forward indefinitely under IRC §1211(b) and §1212(b). So the most useful amount to harvest in a year is your net gain plus $3,000. Losses beyond that do not cut this year's tax, but they bank a carryforward for future gains.

This calculator is for informational purposes only. Its results are estimates based on the rates you enter and simplified netting, not a completed Schedule D.

For broader planning, read capital gains tax strategies, and use the capital gains tax calculator to price the gains you are offsetting.

How the calculator works

1. Net position before harvesting: realized gains − realized losses − carryforward. In the default example: $15,000 − $5,000 − $8,000 = $2,000 of net gain, which costs $300 at 15%.
2. Losses that cut this year's tax: net gain + the capital loss limit, capped at your unrealized losses. Here: $2,000 + $3,000 = $5,000.
3. Tax saved this year: $2,000 of gain no longer taxed at 15% ($300) plus $3,000 of ordinary income no longer taxed at 22% ($660) = $960.
4. Carryforward if you harvest everything: the remaining $20,000 of unrealized losses would carry forward. Valued at 15% against future long-term gains, that is about $3,000 of future tax, which the calculator adds to show the total potential saving of $3,960.

The calculator reads the $3,000 or $1,500 limit from your filing status. A married couple filing separately in the same situation would get the most out of harvesting $3,500 ($2,000 + $1,500), saving $300 + $330 = $630.

Which tax rates should you enter?

Enter the rates that apply to your next dollar of income. The form shows your federal bracket for the income and filing status you enter as a hint.

• Marginal tax rate: your ordinary bracket plus your state rate, if any. A married couple with $150,000 of income has $117,800 of taxable income after the $32,200 standard deduction, which is in the 22% bracket for 2026 (not 32%).
• Long-term capital gains rate: 0%, 15% or 20% depending on taxable income, plus 3.8% net investment income tax if your modified AGI is above $200,000 ($250,000 joint). The NIIT calculator shows whether that applies.
• Short-term capital gains rate: short-term gains are taxed like ordinary income, so this is usually the same as your marginal rate.

2026 long-term capital gains brackets

These are taxable-income thresholds from Rev. Proc. 2025-32. If your taxable income is inside the 0% band, harvesting losses against long-term gains saves nothing this year and you may be better off harvesting gains instead.

How capital losses are netted on Schedule D

You do not choose which gains a loss offsets. Schedule D nets in a fixed order:

1. Short-term losses offset short-term gains, and long-term losses offset long-term gains.
2. A net loss in one category then offsets a net gain in the other.
3. A net loss overall offsets up to $3,000 of ordinary income; the rest carries forward, keeping its short-term or long-term character.

That order matters for the value of a harvest. A short-term loss used against short-term gains saves your ordinary rate; a long-term loss that ends up offsetting long-term gains saves only 15% or 20%. The calculator treats all gains and losses as one type, priced at the long-term rate, and shows a second figure for the case where the gains you offset are short-term. In the default example the same $5,000 harvest saves $1,100 if the $2,000 of gain is short-term ($2,000 × 22% + $3,000 × 22%).

The wash sale rule

Under IRC §1091, a loss is disallowed if you acquire substantially identical stock or securities within 30 days before or after the sale, a 61-day window. The disallowed loss is not gone: it is added to the cost basis of the replacement shares, and their holding period includes the time you held the old ones. Publication 550 covers the details.

Purchases that trigger a wash sale include:

• Buying the same stock, fund or ETF in any of your taxable accounts.
• Buying it in your IRA or Roth IRA. Under Rev. Rul. 2008-5, the loss is disallowed and is not added to the IRA's basis, so it is lost permanently.
• A purchase by your spouse, or by a corporation you control.
• Reinvested dividends in the same fund within the window, even small ones. Turn off automatic reinvestment before you harvest.
• Buying a call option on the same stock.

Staying invested without a wash sale

The usual approach is to buy something similar but not substantially identical, then switch back after 31 days if you want:

The IRS has never published a bright-line test for funds. Two share classes of the same fund, or two ETFs tracking the exact same index, are the riskiest swaps.

Cryptocurrency held as property is generally not a stock or security under §1091 under current federal law. If you are harvesting bitcoin or ether, read crypto tax-loss harvesting and price the sale with the crypto capital gains tax calculator.

Is tax-loss harvesting worth it?

The tax you save this year is real, but part of it is borrowed from the future. When you sell a fund at a loss and buy a similar one, the new position starts with a lower cost basis, so the gain you avoid now shows up when you eventually sell the replacement. Harvesting creates lasting value in four ways:

• Rate arbitrage: the $3,000 ordinary offset saves your ordinary rate (22% in the example) on a loss that might later only have offset a 15% gain.
• Short-term versus long-term: losses that offset short-term gains save your ordinary rate, while the deferred gain may later be taxed at long-term rates.
• Deferral: paying tax years later is worth something even at the same rate, because the money stays invested.
• Never paying it: if you hold the replacement until death, your heirs get a stepped-up basis, and if you donate it to charity, the gain is never taxed.

Harvesting is least useful when you are in the 0% capital gains bracket, when the loss is small relative to trading costs and bid-ask spreads, or when you expect to sell the replacement soon in a higher bracket.

Year-end checklist

• Pull your realized gains and losses from each broker's year-to-date gain/loss report, including mutual fund capital gain distributions, which are usually paid in December.
• Find your carryforward on last year's Schedule D (Capital Loss Carryover Worksheet).
• Harvest by the last trading day of the year. Sales settle later, but the trade date determines the tax year for a loss.
• Check every account in your household, including IRAs and your spouse's accounts, for purchases inside the 61-day window.
• Use specific-lot identification so you sell the lots with the largest losses rather than the oldest shares.

Where harvested losses come from

Losses often exist inside a portfolio that is up overall, because individual lots were bought at higher prices. Dollar-cost averaging into a fund every month, for example, creates dozens of lots, and the most recent ones may be underwater even when the fund is above your average cost. Check lot-level gains, not just the position total.

Losses on a personal residence or personal-use property are not deductible, and losses in IRAs and 401(k)s cannot be harvested at all. For rental and investment real estate, see the real estate capital gains calculator.

What the calculator does not include

• Separate short-term and long-term netting (one blended rate is used, with a short-term comparison).
• The 0% capital gains band: if your gains fall in it, enter 0% as your long-term rate.
• State rules that differ from federal treatment of capital losses.
• Investment-level wash sale tracking across accounts.

For more on the difference between short-term and long-term rates, see short-term vs. long-term capital gains tax rates.