Share Incentive Plan Calculator: Estimate Your
UK SIP and US ESPP Returns

A share incentive plan is one of the most tax-efficient employee benefits available, whether you are participating in a UK Share Incentive Plan (SIP) or a US Employee Stock Purchase Plan (ESPP). This share incentive plan calculator estimates your tax savings, employer match value, and the after-tax position of your shares for both markets.

For UK SIP participants, the calculator works through the four share types (free, partnership, matching, dividend), the 5-year tax-free hold, and your effective contribution cost after PAYE and NI relief. For US ESPP participants, it models the discount, look-back provisions, qualifying versus disqualifying dispositions, and federal and FICA tax impact.

Enter your country, salary, contribution rate, employer match or ESPP discount, and share price, and the calculator returns your projected gains in either currency.

✅ Supports UK SIP and US ESPP scenarios

✅ Covers the UK 5-year tax-free hold and US qualifying disposition rules

✅ Estimates UK PAYE/NI or US federal/FICA tax impact

✅ Free to use, no signup required