Startup equity vs BigCo RSU.

Choosing between startup and big company role: startup pays less cash but offers equity upside if the company succeeds. Big company pays higher base + RSUs (predictable). This tool compares total expected value over a typical 4-year vesting period using probability-weighted equity outcomes.

Startup: 80k salary × 4 = 320k cash + 0.5% × 100M valuation × 20% exit probability = 100k expected equity. Total: 420k. BigCo: 130k + 40k RSUs × 4 = 680k. BigCo wins by 260k. But startup has higher upside (10% exit at higher valuation = 500k+ equity) and lower downside (still gets cash). Risk profile differs even when expected values close.

Reality check on startup equity: 90%+ of startup equity is worth zero. The 10% that exits typically returns 10-100x. So 0.5% in a startup that exits at 500M = 2.5M. The 1-in-10 outcome justifies expected value calculations even when most outcomes are zero. Diversify by working at multiple startups across career, not just one.

Quick example

With startup annual salary of 80,000 and startup equity of 0.5% (plus startup valuation of 100,000,000 and exit probability of 20%), the result is -260,000.00. Change any figure and watch the output shift — it's often more useful to see the pattern than to memorise the formula.

Which inputs matter most

You enter Startup Annual Salary, Startup Equity %, Startup Valuation, Exit Probability %, and BigCo Annual Salary. Two inputs usually tip the answer one way or the other. Identify which ones matter most by flipping each value past a round threshold and watching whether the winning option changes.

What's happening under the hood

Startup total = salary × years + equity % × valuation × exit prob. BigCo total = (salary + RSU) × years. The formula is listed in full below. If the number looks off, you can retrace the calculation by hand — that's the point of showing the working.

Why small rate shifts add up

A 3% pay rise looks modest. Apply it over a 30-year career with modest promotions and the lifetime difference runs to six figures. This calculator makes that invisible compounding visible in a way spreadsheets usually don't.

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.