FinToolSuite

Equity Option Breakeven Calculator

Updated April 17, 2026 · Income · Educational use only ·

Share price needed for options to be worth exercising.

Find the share price needed for stock options to break even after exercise cost and tax. Enter strike price to see breakeven price and current paper value.

What this tool does

Stock options are only valuable if the share price exceeds the strike price by enough to cover exercise tax. Enter strike price, total options, marginal tax rate, and current share price. The tool shows the breakeven price and current paper value.


Enter Values

Value is unusually high — please double-check

Formula Used
Strike price per share
Marginal rate as a decimal

Spotted something off?

Calculations, display, or translation — let us know.

Disclaimer

Results are estimates for educational purposes only. They do not constitute financial advice. Consult a qualified professional before making financial decisions.

10,000 options at a 5 strike with a 40% marginal rate need the share price to reach 8.33 just to cover exercise tax — at 8 today the options are net negative if exercised. Knowing the breakeven helps decide whether to exercise now, wait, or let them expire.

What the result means

Breakeven price is the share price needed for the options to be net positive after exercise tax. Paper value is the current intrinsic value if exercised today, after tax. A negative paper value means exercising now would lose money.

Long-term capital gains treatment after exercise is not modelled — the tool assumes worst-case ordinary-income tax. If your jurisdiction grants favourable treatment (ISOs, EMI), the breakeven is lower than shown.

Run it with sensible defaults

Using strike price of 5, total options of 10,000, marginal tax rate of 40%, current share price of 8, the calculation works out to 8.33. Nudge the inputs toward your own situation and the output recalculates instantly. The defaults are meant as a starting point, not a recommendation.

The levers in this calculation

The inputs — Strike Price, Total Options, Marginal Tax Rate, and Current Share Price — do not pull with equal force. Not every input has equal weight. Flip one at a time toward extreme values to feel which ones move the needle most for your situation.

How the math works

Breakeven price is strike divided by one minus the tax rate. Paper value at the current price is options times (current price minus strike) times one minus tax rate. The working is transparent — you can verify every step yourself in the formula section below. No black box, no opaque "proprietary model".

What the headline number hides

Gross pay, net pay, and what actually lands in your account can differ by thousands depending on tax code, benefits, pension contributions, and student loan deductions. This tool isolates one piece of that picture — always pair it with a take-home calculator for the full view.

What this doesn't capture

Tax bands, pension contributions, student-loan deductions, and benefits-in-kind sit outside this calculation. The figure is the headline; your actual position depends on local tax rules and personal circumstances. Pair with a dedicated take-home calculator for the full picture.

Example Scenario

Your options break even when the share price reaches the figure shown above.

Inputs

Strike Price:5 £
Total Options:10,000
Marginal Tax Rate:40
Current Share Price:8 £
Expected Result£8.33

This example uses typical values for illustration. Adjust the inputs above to match a specific situation and see how the result changes.

Sources & Methodology

Methodology

Breakeven price is strike divided by one minus the tax rate. Paper value at the current price is options times (current price minus strike) times one minus tax rate.

Frequently Asked Questions

Why does breakeven move with tax?
The exercise gain is taxed as income. Higher tax means more of the gain is lost, so the price has to climb further before the post-tax position turns positive.
EMI or ISO treatment?
Tax-favoured schemes can mean the gain is taxed at lower capital gains rates instead of income rates. Use the lower rate as the marginal rate to model that benefit.
When should I exercise?
Exercising when the price is above breakeven and you believe in the company's prospects locks in tax at today's spread. Waiting may grow the gain but exposes you to share-price falls.
What about exercise cost itself?
You also need cash to pay the strike. Cashless exercise (sell-to-cover) is sometimes available — it sells enough shares to cover both strike and tax.

Related Calculators

More Income Calculators

Explore Other Financial Tools