Methodology, rates and sources
This page lists the figures our calculators use and where they come from, so you can check them. Review date: October 2026. Tax year: 2026/27.
Rates used
| Item | Figure used |
|---|---|
| Income tax (England, Wales, NI) | 20% basic, 40% higher, 45% additional (marginal) |
| Employee National Insurance | 8% on earnings up to the upper earnings limit, 2% above |
| CGT rates | 18% basic rate, 24% higher and additional rate |
| Business Asset Disposal Relief | 18% from 6 April 2026 |
| CGT annual exempt amount | £3,000 |
| SIP limits | Partnership: lower of £1,800 or 10% of salary; free shares £3,600; matching up to 2:1 |
| EMI limits | £250,000 per employee; £3m company limit |
| CSOP / SAYE | £60,000 options; £500 a month savings |
Assumptions that apply to every calculator
- Marginal rates are held constant; the personal allowance taper above £100,000 is not modelled.
- Scottish income tax rates differ and are not included.
- Growth is a constant annual percentage; real share prices are volatile.
- Calculations run in your browser. Nothing you enter is sent to or stored on our servers.
Official sources
- GOV.UK: Tax and employee share schemes
- HMRC Employee Tax Advantaged Share Scheme User Manual
- GOV.UK: Capital Gains Tax rates and allowances
- GOV.UK: Income Tax rates and bands
Corrections
If you believe a figure is out of date or wrong, email contact@shareincentivecalculator.com. We review rates each tax year and after every Budget.
Written and maintained by the EquityCalc Hub editorial team. Tax figures reviewed for the 2026/27 UK tax year. Last updated October 2026. See our methodology and sources. This page is general information, not tax or financial advice.