Tool · Investor Sam Taxes

Tax-Loss Harvesting Savings Calculator

July 1, 2026 • By the Investor Sam Editorial Team • Reviewed by Berly Sam Varghese, Editor
Tax-loss harvesting turns a losing investment into a tax asset. The IRS lets you use capital losses to offset capital gains dollar-for-dollar, and deduct up to $3,000 of excess losses against ordinary income each year. This tool calculates the precise tax saved at your rates, accounting for whether you have short-term gains to offset (more valuable) or are limited to the $3,000 annual cap.

Example: Loss amount to harvest: 10000 $ · Annual taxable income: 110000 $ · Filing status (0 = Single, 1 = Married Filing Jointly): 0 · Do you have short-term gains to offset? (0 = No, 1 = Yes): 1 · State income tax rate: 5 %

Total tax saved (federal + state)$2,833
Federal tax saved$2,333
State tax saved$500
Effective harvest rate (savings as % of loss)28.33%

Worked example

A single filer with $110,000 income and short-term gains to offset harvests a $10,000 loss. At a 22% federal marginal rate + 5% state rate, the $10,000 loss saves $2,200 federal + $500 state = $2,700 total — an effective harvest rate of 27%. Without short-term gains, the $3,000 annual cap limits federal savings to $660 in year 1, with the rest carried forward.

Frequently asked questions

What is the wash-sale rule?

You cannot repurchase the same or a substantially identical security within 30 days before or after the sale that generated the loss. Doing so disallows the loss. The 30-day window applies on both sides of the sale date. Buying a similar-but-not-identical ETF (e.g., switching from SPY to IVV) generally avoids the rule.

Can unused capital losses carry forward forever?

Yes. Capital losses that exceed the annual $3,000 ordinary income deduction carry forward indefinitely. They retain their character (short-term losses first offset short-term gains; long-term losses offset long-term gains, then cross-apply). There is no expiration.

Does tax-loss harvesting make sense in a tax-advantaged account?

No. Losses inside a traditional IRA, Roth IRA, or 401(k) are not deductible — there is no tax benefit from realizing a loss inside a sheltered account. Tax-loss harvesting applies only to taxable brokerage accounts.

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Sources

Berly Sam Varghese · Editor, Investor Sam

Berly Sam Varghese is an engineer who treats money the way he treats any hard problem — something to be engineered, not gambled on. He funded years of education and built real financial stability the patient way, by living below his means and investing rather than borrowing. He writes for the person trying to plan around a tax bill that feels immovable. He reviews and approves every article on Investor Sam and checks the figures against primary sources before anything is published. More about our standards.