Tax-Loss Harvesting Calculator

See how selling losing investments can reduce your tax bill.

Investment Gains & Losses

Tax Savings from Harvesting

Total Tax Savings
$3,450
23% effective benefit on $15,000 in losses
How Loss Is UsedAmountTax RateSavings
Short-term gains offset$5,00024% + 5% state$1,450
Long-term gains offset$10,00015% + 5% state$2,000

Strategy Tips

  • 1.Offsetting short-term gains saves the most — they're taxed at your 24% ordinary rate
  • 2.Wash sale rule: don't buy the same or 'substantially identical' security within 30 days before or after selling at a loss
  • 3.Consider replacing sold positions with similar (not identical) ETFs to maintain market exposure

This is a simplified estimate. Consult a tax advisor for specific guidance on tax-loss harvesting strategies.

How Tax-Loss Harvesting Works

Tax-loss harvesting means selling investments at a loss to offset capital gains and reduce your tax bill. Losses first offset same-type gains (short-term losses offset short-term gains), then offset the other type. Excess losses up to $3,000/year can be deducted from ordinary income. Any remaining losses carry forward indefinitely. The strategy works best in taxable brokerage accounts — not IRAs or 401(k)s, which are already tax-advantaged.

Loss Offset Priority Rules

StepActionTax Impact
1Offset short-term gainsSaves at ordinary income rate (10–37%)
2Offset long-term gainsSaves at LTCG rate (0%, 15%, or 20%)
3Deduct $3,000 from ordinary incomeSaves at marginal rate
4Carry forward remaining lossesUse in future tax years

Annual Tax Savings by Bracket

Federal Bracket$10K Short-Term Offset$10K Long-Term Offset$3K Ordinary Deduction
12%$1,200$0 (0% LTCG rate)$360
22%$2,200$1,500$660
24%$2,400$1,500$720
32%$3,200$1,500$960
37%$3,700$2,000$1,110

Frequently Asked Questions

What is the wash sale rule?

The wash sale rule prevents you from claiming a loss if you buy the same or "substantially identical" security within 30 days before or after the sale. If you sell an S&P 500 index fund at a loss, you can't buy a different S&P 500 index fund — but you could buy a total stock market fund or a large-cap fund that tracks a different index. The IRS hasn't clearly defined "substantially identical," so most advisors recommend switching to a different index entirely.

Is tax-loss harvesting worth the effort?

For portfolios over $100,000 in taxable accounts, harvesting typically saves $1,000–$5,000+ annually depending on market conditions and your tax bracket. Studies show systematic tax-loss harvesting can add 0.5–1.5% to after-tax returns annually. The key is consistency — harvesting throughout the year, not just in December.

See also: Capital Gains Tax Calculator and Dividend Income Calculator.