Wash Sale Rule Calculator
Check if a stock repurchase triggers the wash sale rule. See adjusted cost basis.
Wash Sale Triggered?
Yes
Disallowed Loss
$5,000.00
Adjusted Basis
$14,500.00
Wash Sale Analysis
| Days Between Sale and Repurchase | 10 days |
| Within 30-Day Window? | Yes — wash sale applies |
| Total Loss on Sale | $5,000.00 |
| Disallowed Loss | $5,000.00 |
| Currently Deductible Loss | $0.00 |
Adjusted Cost Basis
| Original Basis Per Share | $95.00 |
| Disallowed Loss Added | $50.00 |
| Adjusted Basis Per Share | $145.00 |
Alternative Strategies
| Wait 31+ days | Repurchase after wash sale window |
| Buy similar (not identical) fund | E.g., switch S&P 500 ETFs from SPY to VOO |
| Double up | Buy first, wait 31 days, then sell original |
| Harvest in tax-advantaged account | Buy replacement in IRA (different rules apply) |
Use the Wash Sale Rule Calculator above to calculate your results. Enter your values and see instant results — all calculations run in your browser.
Disclaimer: This calculator is for informational purposes only and does not constitute tax, financial, or legal advice. Results are estimates based on the information you provide and current rates. Always consult a qualified tax professional or financial advisor for advice specific to your situation.
How It Works
Determine if your stock repurchase will trigger the IRS Wash Sale Rule, which could prevent you from claiming a capital loss. Our calculator helps you understand the impact on your adjusted cost basis, crucial for accurate tax reporting in 2026. Avoid unexpected tax liabilities by understanding this complex rule.
The calculator identifies a wash sale if you sell stock at a loss and then buy substantially identical stock within 30 days before or after the sale date (a 61-day window). If a wash sale occurs, the disallowed loss is added to the cost basis of the newly acquired stock, increasing it by that amount.
A common mistake is forgetting to account for all identical securities, including options or ETFs that track the same underlying asset. Remember, the rule applies even if the repurchase is in a different account (e.g., IRA vs. taxable brokerage). Don't solely focus on the exact stock ticker.
Example: Wash Sale Impact
- 1 Input: You sold 100 shares of XYZ Corp. on April 1, 2026, at $50 per share, realizing a $500 loss (original cost basis was $55 per share). You then repurchase 100 shares of XYZ Corp. on April 15, 2026, at $52 per share.
- 2 Calculation: Since the repurchase occurred within 30 days of the sale at a loss, a wash sale is triggered. The $500 loss is disallowed. This $500 is added to the cost basis of your newly acquired shares.
- 3 Result: Your adjusted cost basis for the 100 shares purchased on April 15, 2026, is $5,700 ($5,200 purchase price + $500 disallowed loss). Your per-share adjusted cost basis is $57.00.
- 4 Context: You cannot claim the $500 loss on your 2026 tax return. Instead, it effectively reduces any future capital gains or increases any future capital losses when you eventually sell the repurchased shares, due to the higher cost basis.
Source: SEC · Last updated: April 2026
Frequently Asked Questions
What is the wash sale rule? (detailed)
Does the wash sale rule apply to crypto?
Can I buy a similar ETF to avoid a wash sale?
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