About the Tax-Loss Harvesting Calculator
This tax-loss harvesting calculator estimates how much tax you save by selling investments that are worth less than you paid. Enter the gains you have already realized this year, the short-term and long-term losses you could harvest, any capital loss carried over from earlier years, and your tax rates. It nets the gains and losses the way Schedule D does and compares your tax with and without the harvest.
Short-term losses first offset short-term gains, which are taxed at ordinary income rates, and long-term losses offset long-term gains, taxed at 0%, 15% or 20% (for 2026 the 0% rate applies to taxable income up to $49,450 single or $98,900 joint, and 20% starts above $545,500 single or $613,700 joint). Any remaining net loss in one category offsets gains in the other, then up to $3,000 a year ($1,500 married filing separately) can be deducted against ordinary income. Anything left carries forward indefinitely.
It is useful near year-end for investors with taxable brokerage accounts and for crypto holders. Remember the wash-sale rule: if you buy the same or a substantially identical security within 30 days before or after the sale, the loss is disallowed for stocks and funds. Harvesting also lowers your cost basis, so part of the benefit is a tax deferral rather than a permanent saving. For simplicity, flat rates are used instead of full bracket calculations, any prior-year carryover is treated as short-term, and the $3,000 deduction is valued at your ordinary federal plus state rate.
With the default inputs, the tax saved by harvesting is $2,850.00. Change any value above to recalculate instantly.
How to use the tax-loss harvesting calculator
- 1Enter the short- and long-term gains you have already realized this year.
- 2Enter the unrealized losses you could sell, split by holding period.
- 3Add any capital loss carryover from last year’s return.
- 4Enter your ordinary, capital gains and state tax rates.
- 5Compare the tax with and without harvesting, and note any carryforward.
Formula and method
Gains and losses are netted in the same order as Schedule D. Short-term results are netted together and long-term results are netted together. If one category ends negative, that net loss reduces the other category’s gain. If the combined result is still a loss, up to $3,000 ($1,500 married filing separately) is deducted from ordinary income and the rest carries forward.
Short-term gains are taxed at your ordinary rate and long-term gains at your capital gains rate, both plus any state tax and the 3.8% net investment income tax when it applies. Tax saved is the difference between the tax with no harvested losses and the tax with them. Prior-year carryover losses are treated as short-term, and flat rates are used rather than full bracket calculations.
- ST, LT
- Net short-term and long-term capital gain
- offset
- Capital loss deducted against ordinary income
Worked examples
Offsetting $25k of gains with $12k of losses
Without harvesting, $5,000 of short-term gain at 29% and $20,000 of long-term gain at 20% cost $5,450. Harvesting $8,000 of short-term losses wipes out the short-term gain and $3,000 more offsets long-term gain; $4,000 of long-term losses cut it further to $13,000, taxed at $2,600.
No gains: deduct $3,000 and carry the rest
With no gains to offset, $3,000 of the $10,000 loss is deducted from ordinary income, saving 29% × $3,000 = $870 this year. The other $7,000 carries forward.
High earner with NIIT and 20% rate
Each dollar of long-term gain costs 20% + 9.3% + 3.8% = 33.1%. Harvesting $30,000 of losses reduces the taxable gain to $70,000 and saves $9,930.
Frequently asked questions
What is tax-loss harvesting?+
It is selling investments that have fallen below what you paid so the realized loss offsets capital gains — and up to $3,000 of ordinary income — reducing this year’s tax. You usually reinvest the money in a similar, but not identical, investment to stay invested.
How much capital loss can I deduct per year?+
Losses offset any amount of capital gains. Beyond that, you can deduct up to $3,000 a year against ordinary income ($1,500 if married filing separately). Unused losses carry forward indefinitely until used.
What is the wash-sale rule?+
If you buy the same or a substantially identical stock, fund or option within 30 days before or after selling at a loss, the loss is disallowed and added to the basis of the new shares. It also applies to purchases in an IRA.
Does the wash-sale rule apply to crypto?+
Under current law the wash-sale rule applies to stocks and securities, and cryptocurrency held as property has not been covered. Proposals to extend it have been made, so check the rules for the year you sell.
Is tax-loss harvesting worth it?+
It is most valuable when you have short-term gains or high ordinary rates. Because harvesting lowers your cost basis, some of the saving is a deferral: you may pay more tax when you eventually sell the replacement, unless you hold until death or donate it.
Tax results are estimates based on published rules and simplified assumptions. They are not tax advice — check official guidance or a tax professional for your situation.