Wash Sale Rule Calculator
Check whether your stock sale and repurchase triggers a wash sale under IRS Section 1091. Enter your sale and purchase dates to see if you're inside the 61-day window, calculate your adjusted cost basis, and understand the tax impact of any disallowed loss.
Wash Sale Determination
YES — Wash Sale$2,000 loss disallowed
Any repurchase of substantially identical securities within 30 days before or after the sale date triggers the wash sale rule.
Window Start (−30d)
May 16, 2025
Sale Date
Jun 15, 2025
Window End (+30d)
Jul 15, 2025
Repurchase Date
Jun 20, 2025
+5d from sale
| Per Share | Total | |
|---|---|---|
| Original cost basis | $100.00 | $10,000 |
| Sale price | $80.00 | $8,000 |
| Total loss | −$20.00 | −$2,000 |
| Disallowed loss | −$20.00 | −$2,000 |
| Repurchase price | $82.00 | $8,200 |
| Adjusted basis (replacement shares) | $102.00 | $10,200 |
Marginal Rate
22.0%
Deferred Tax Benefit
$440
Embedded in adjusted basis
Deferred, not lost: The $440 tax benefit is preserved in your adjusted cost basis of $102.00/share. You will realize it when you eventually sell the replacement shares.
Cross-account warning (IRA trap)▼
Substantially identical securities▼
Year-end trap▼
How the wash sale rule works
The 61-day window
The wash sale window covers 30 days before the sale, the sale date itself, and 30 days after — a total of 61 days. Buying the same or substantially identical security anywhere in this window triggers the rule.
Basis adjustment
The disallowed loss is not gone forever. It is added to the cost basis of your replacement shares, so you'll recover it when you eventually sell those shares. The holding period from the original shares also carries over.
Cross-account traps
The wash sale rule applies across all accounts — brokerage, IRA, Roth IRA, and even a spouse's accounts. Repurchasing in an IRA after a taxable-account loss permanently disallows the loss since IRA cost basis cannot be adjusted.
Partial wash sales
If you repurchase fewer shares than you sold, only a proportional portion of the loss is disallowed. The rest of the loss remains deductible. Track each lot separately for accurate calculations.
Worked example — disallowed loss and basis bump
You buy 100 shares at $50 ($5,000), sell all 100 at $30 ($3,000) for a $2,000 loss, then repurchase 100 shares at $32 ten days later — inside the 61-day window.
- Wash sale triggered: yes (100 of 100 shares repurchased in the window)
- Disallowed loss (deferred, not lost): $2,000
- Loss you can still deduct this year: $0
- Adjusted cost basis of the replacement shares: $52.00/share ($5,200 total)
- You recover the $2,000 when you sell the replacement shares — the basis bump means you break even at $52.00/share.
What counts as "substantially identical"?
| Triggers the rule | Generally does NOT |
|---|---|
| Same stock or ETF (and contracts/options to buy it) | A different company in the same sector |
| Repurchase in your IRA or your spouse's account | A different index fund tracking a different index |
| Buying back within 30 days before or after the sale | Cryptocurrency (treated as property, not a security) |
| Two funds tracking the same index (IRS may treat as identical) | Waiting 31+ days before repurchasing |
Frequently asked questions
What is the wash sale rule?
The wash sale rule (IRS Section 1091) disallows a tax loss deduction if you buy the same or a substantially identical security within 30 days before or after selling at a loss. The 61-day window spans 30 days before the sale, the sale date itself, and 30 days after. The disallowed loss is added to the cost basis of your replacement shares.
What happens to the disallowed loss in a wash sale?
The disallowed loss is not permanently lost — it is added to the cost basis of your replacement shares. This means you'll effectively recover the loss when you eventually sell the replacement shares. Your holding period from the original shares also carries over.
Does the wash sale rule apply across different accounts?
Yes. The wash sale rule applies across all your accounts — brokerage, IRA, Roth IRA, 401(k), and even your spouse's accounts. Critically, if you sell at a loss in a taxable account and repurchase in an IRA, the loss is permanently disallowed because you cannot adjust the IRA's cost basis.
Does the wash sale rule apply to cryptocurrency?
The wash sale rule does not apply to cryptocurrency for 2025 or 2026. The IRS treats crypto as property, not a security, so IRC §1091 does not reach it — meaning crypto investors can sell at a loss and immediately repurchase. Proposals to extend the wash sale rule to digital assets were considered during the One Big Beautiful Bill Act but were NOT included in the final law. This could still change if Congress passes a future digital-asset tax bill, so check current rules before relying on crypto loss harvesting.
Sources
Related Calculators
Tax-Loss Harvesting
Capital loss utilization, $3k annual deduction, carryforward
Capital Gains Tax Calculator
LTCG 0/15/20% rates + 3.8% NIIT based on income brackets
Federal Income Tax Calculator
10–37% brackets, $15,750 standard deduction, progressive calculation
Crypto Tax Calculator
STCG ordinary rates, LTCG 0/15/20%, mining/staking income
NIIT Calculator
Net Investment Income Tax 3.8%, thresholds $200k / $250k MFJ
Dividend Tax Calculator
Qualified 0/15/20% rates vs ordinary income + 3.8% NIIT