{
  "slug": "wash-sale-risk-window",
  "title": "Wash Sale Risk Window Calculator",
  "heading": "Wash Sale Rule Date Calculator",
  "category": "financial",
  "url": "https://www.revenuelab.fyi/toolbox/wash-sale-risk-window",
  "summary": "Find the exact dates you must avoid repurchasing a security after a tax-loss sale.",
  "description": "The wash sale rule disallows a tax loss if you buy the same or a substantially identical security within a 61-day window: 30 days before the sale through 30 days after it. Miss this window by even a day and the IRS disallows the loss deduction, instead adding the disallowed loss to the cost basis of the new shares (deferring, not destroying, the benefit — but not in the year you wanted it). This calculator takes your sale date and spits out the exact start and end dates of the no-buy window, plus a reminder about the trickier scenarios: automatic dividend reinvestment inside the same fund can itself trigger a wash sale, and the rule applies across all your accounts, including your spouse's accounts and your IRA, not just the one where you sold.",
  "formula": "Window start = sale date − 30 calendar days. Window end = sale date + 30 calendar days. Safe repurchase date = window end + 1 day.",
  "dateModified": "2026-09-30",
  "run_url": "https://www.revenuelab.fyi/api/public/calc?tool=wash-sale-risk-window",
  "inputs": [
    {
      "id": "saleDate",
      "label": "Date you sold at a loss",
      "kind": "date",
      "hint": null,
      "default": "2024-12-15"
    }
  ],
  "outputs": [
    {
      "id": "safeDate",
      "label": "First safe repurchase date",
      "format": "raw",
      "hint": null,
      "primary": true
    },
    {
      "id": "windowStart",
      "label": "Window starts (30 days before sale)",
      "format": "raw",
      "hint": null,
      "primary": false
    },
    {
      "id": "windowEnd",
      "label": "Window ends (30 days after sale)",
      "format": "raw",
      "hint": null,
      "primary": false
    },
    {
      "id": "totalWindowDays",
      "label": "Total no-buy window",
      "format": "number",
      "hint": null,
      "primary": false
    }
  ],
  "worked_example": {
    "inputs": [
      "Date you sold at a loss: 2024-12-15"
    ],
    "outputs": [
      "First safe repurchase date: 2025-01-15",
      "Window starts (30 days before sale): 2024-11-15",
      "Window ends (30 days after sale): 2025-01-14",
      "Total no-buy window: 61"
    ]
  },
  "how_to": {
    "title": "How to use this",
    "steps": [
      "Enter date you sold at a loss.",
      "Read your first safe repurchase date on the right — it updates as you type.",
      "Hit Share to keep the scenario or send it to someone."
    ]
  },
  "scenarios": [
    {
      "name": "Conservative",
      "description": "Lower-end numbers — what if things land soft?",
      "values": {
        "saleDate": "2024-12-15"
      }
    },
    {
      "name": "Typical",
      "description": "Defaults — the most common real-world setup.",
      "values": {
        "saleDate": "2024-12-15"
      }
    },
    {
      "name": "Ambitious",
      "description": "Higher-end numbers — what if things really pop?",
      "values": {
        "saleDate": "2024-12-15"
      }
    }
  ],
  "limitations": [
    "Results are estimates before tax, fees, and inflation unless an input explicitly covers them.",
    "Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.",
    "This is educational maths, not financial advice. Check anything contractual with the lender or your accountant."
  ],
  "faq": [
    {
      "q": "Does the wash sale rule apply if I buy in a different account?",
      "a": "Yes. The IRS aggregates across all accounts you control, including a spouse's accounts filing jointly and even your own IRA. Buying the same stock in your Roth IRA within the window after selling it at a loss in your taxable account still triggers a wash sale — and worse, in that case the disallowed loss is permanently lost, not just deferred, since IRAs don't carry a cost basis adjustment the same way."
    },
    {
      "q": "What counts as 'substantially identical'?",
      "a": "The same stock or bond, definitely. Different but very similar index funds tracking the same index (like two different S&P 500 funds from different providers) are a gray area the IRS hasn't clearly ruled on, but most practitioners treat them as safe since they're legally distinct securities from different issuers. Options and warrants on the same underlying stock can also count."
    },
    {
      "q": "Can automatic dividend reinvestment trigger a wash sale?",
      "a": "Yes, and it's an easy one to miss. If a fund pays a dividend and automatically reinvests it into more shares of the same fund within the 61-day window around a loss sale of that same fund, the reinvested shares can trigger a wash sale on part of your loss. Turn off auto-reinvest before harvesting a loss if you plan to sell soon."
    },
    {
      "q": "What happens to the disallowed loss?",
      "a": "It's not gone — it gets added to the cost basis of the replacement shares you purchased, and the holding period may also carry over. You'll effectively recapture the benefit whenever you eventually sell those replacement shares for good, just not in the year you wanted."
    }
  ],
  "related": [
    "https://www.revenuelab.fyi/toolbox/tax-loss-harvesting-benefit",
    "https://www.revenuelab.fyi/toolbox/ltcg-zero-bracket-harvesting",
    "https://www.revenuelab.fyi/toolbox/asset-location-tax-efficiency"
  ],
  "license": "CC-BY-4.0",
  "citation": "RevenueLab — Wash Sale Risk Window Calculator (https://www.revenuelab.fyi/toolbox/wash-sale-risk-window)"
}