Wash Sale Calculator: Calculate Your Adjusted Cost Basis Easily

Use this wash sale calculator to accurately determine the adjusted cost basis of your stocks after a wash sale event.

Wash Sale Calculator:

Use this calculator to determine if your securities sale can be considered a wash sale. A wash sale occurs when you sell a security at a loss and then purchase the same or a “substantially identical” security within 30 days before or after the sale. If identified, the loss from the wash sale is not deductible.

How to Use:

Enter the sell price, buy price, and the number of shares. Click the “Calculate” button to get the results. The calculator will show whether the sale was a wash sale and the denied loss amount if applicable.

How It Calculates:

The calculator assesses if the sale is a wash sale by comparing the sell price and the buy price:

  • If the sell price is less than the buy price, you have a loss.
  • If the buy of the same or substantially identical security occurred within 30 days of this sale, the loss could be denied for tax purposes.

Result will show “No Wash Sale” if the conditions don’t meet the criteria, otherwise it will display “Wash Sale with $X loss disallowed”, with “X” being the amount of loss that can’t be claimed.


This calculator does not account for all tax situations and regulations. It should not be used as a substitute for professional tax advice. Additionally, it assumes that the same number of shares were bought and sold and does not take into account multiple purchases or sales within the 30-day window.

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