ESPP Calculator
An employee stock purchase plan lets you buy company stock at a discount — often 15% below market, sometimes with a lookback to the lower price. This calculator shows the deal in dollars.
How this calculator works
With a lookback provision, your purchase price is the lower of the offering-date price or the purchase-date price, minus the discount — with a 15% discount that can be a big gap. The calculator buys shares at that price with your total contribution, then values them at the current price. The difference between your contribution and that value is the instant gain, before you sell or pay tax on it.
Frequently asked questions
What does 'lookback' mean in an ESPP?
A lookback provision lets you buy at the lower of the price at the start of the offering period or the price at purchase. When the stock rises during the period, you get both the discount and the price appreciation — the best case for an ESPP.
How is ESPP discount taxed?
A qualified ESPP (under Section 423) gets favorable treatment if you hold the shares long enough: the discount is ordinary income, and any additional gain may be taxed at capital gains rates. Selling immediately makes the entire gain ordinary income.
Should I sell ESPP shares right away?
Many financial advisors recommend selling immediately for diversification, since the discount is a guaranteed return and holding concentrates risk in your employer's stock — which is also your job. Tax rules make the decision more nuanced; run the numbers both ways.
Disclaimer: Results are estimates for general information only and do not constitute financial, tax, or legal advice. Figures reflect 2026 rules and may change. Always confirm current limits and consult a qualified professional before making decisions. Official figures: IRS.gov · 2026 limits per IRS tax inflation adjustments.