How the equity-vs-salary math works
An equity grant is a promise about the future; a base salary is a paycheck. The whole comparison hinges on four things: how much of the grant actually vests while you're there, what the stock does in that time, how risky that stock is, and how long you stay. Salary is guaranteed and compounds through raises and the 401(k) match — both apply to base pay only, never to equity. Equity can beat it, but only in the worlds where you vest it and the stock cooperates.
The formulas
salary total (Y years) = base × ((1 + r)Y − 1) ÷ r × (1 + 401k match) · equity value = Σ of each vested year's tranche × (1 + growth)year, then × (1 − uncertainty discount) · tranches = grant ÷ vesting years · only years ≤ your stay vest · scenarios: growth − 10 pts (bear), your growth (expected), growth + 10 pts (bull)
The grant is sliced into equal yearly tranches, each grown forward by the stock assumption from year one — earlier tranches get more growth, which is why longer vesting with good growth stacks up. The uncertainty discount is your honest haircut for forfeiture risk, dilution, illiquidity (private stock you can't sell), and volatility. The three scenarios exist because a single growth guess is a lie: they show how wide the answer is before you bet on it.
Worked example: $150,000 + $200,000 grant over 4 years vs $180,000
Offer A pays $150,000 base plus a $200,000 RSU grant vesting over 4 years. Offer B pays $180,000 base, no equity. Assume a 5-year stay, 3% annual raises, a 4% 401(k) match, 5% stock growth, and a 20% uncertainty discount.
1. Salary totals: Offer A: $150,000 × 5.3091 (5 years of 3% raises) × 1.04 = $828,225. Offer B: $180,000 × 5.3091 × 1.04 = $993,870. On salary alone, Offer B leads by $165,645.
2. The equity: $50,000 vests each year, growing at 5%: $52,500 + $55,125 + $57,881 + $60,775 = $226,281. Discount 20% for uncertainty → $181,025.
3. The verdict: Offer A totals $1,009,250; Offer B totals $993,870 — the equity offer wins by $15,380 at expected growth. But the bear path (−5% stock) flips it: Offer A trails by $24,670. The bull path (+15%) stretches the win to $64,050. That swing — from minus $25k to plus $64k — is what the $30,000 of extra salary never has to worry about.
Where this comes in handy
- Comparing two real offers: when one leads with equity and the other with base pay, run both with your honest stay length — not the optimistic one. The stay decides how much vests.
- Pricing the cliff: most grants vest nothing until the one-year mark. If your plan has you leaving in year one, enter a 1-year stay and watch the equity column collapse.
- Discounting private-company paper: stock you cannot sell until an IPO or acquisition deserves a much bigger uncertainty discount — and the range chart shows why the same grant can be worth anywhere from life-changing to $0.
- Asking for more equity instead of salary: when the base is capped by the pay band, the calculator shows the grant size that closes the gap — compare a signing bonus vs a higher salary alongside this one.
- Seeing the after-tax picture: RSUs vest as ordinary income, so the take-home pay calculator shows what each base salary actually deposits.
- Valuing the whole offer: the 1099 vs W-2 calculator breaks down benefits and self-employment tax when the equity offer is really a contractor deal.