Model startup options, shares, dilution, vesting, and taxes. Review ownership percentages, exercise cost, and exits. Make better offer decisions using realistic equity planning numbers.
| Scenario | Granted Shares | FD Shares | Strike | Exit Value | Dilution | Net Result Trend |
|---|---|---|---|---|---|---|
| Early Engineer Offer | 25,000 | 10,000,000 | $0.50 | $250,000,000 | 20% | Moderate upside |
| Senior Hire Offer | 60,000 | 18,000,000 | $1.40 | $600,000,000 | 25% | Higher upside |
| Late Stage Offer | 12,000 | 45,000,000 | $4.10 | $1,000,000,000 | 10% | Lower percentage |
Vested Percent = min((Months Worked ÷ Vesting Term) + Acceleration, 100%) after cliff rules apply.
Vested Shares = Granted Shares × Vested Percent.
Current Ownership = Granted Shares ÷ Current Fully Diluted Shares.
Future Fully Diluted Shares = Current Fully Diluted Shares × (1 + Future Dilution %).
Post-Dilution Ownership = Granted Shares ÷ Future Fully Diluted Shares.
Expected Exit Price Per Share = Expected Company Exit Value ÷ Future Fully Diluted Shares.
Exercise Cost = Vested Shares × Strike Price.
Gross Exit Spread = Vested Shares × max(Expected Exit Price Per Share − Strike Price, 0).
Estimated Net Exit Value = Gross Exit Spread − Estimated Tax.
Breakeven Exit Valuation = Strike Price × Future Fully Diluted Shares.
Startup equity can change the direction of a career. Base salary is important. Ownership can matter even more in a strong exit. Many candidates accept grants without understanding dilution, vesting, or exercise cost. That creates confusion later. A clear calculator reduces that risk. It turns complex offer terms into visible numbers. That helps you compare compensation packages with more confidence. It also helps you ask sharper questions before you sign. Better math usually leads to better career decisions.
This equity startup calculator estimates current ownership, vested shares, and post-dilution ownership. It also estimates exercise cost, current paper spread, and possible exit proceeds. These are useful planning numbers. They do not guarantee a future result. Still, they help you understand the shape of an offer. A small grant at a strong company may beat a larger grant elsewhere. A low strike price may improve upside. A large dilution assumption may lower future ownership materially.
Career planning requires side by side comparison. You should review salary, bonus, role scope, learning value, and equity together. Start with fully diluted shares. Then review vesting. Next, test multiple exit values. Add conservative dilution assumptions. Review the breakeven valuation too. That figure shows when the grant starts to create intrinsic value over the strike price. You should also estimate taxes. Net value matters more than headline value. A realistic model makes negotiations calmer and more practical.
This calculator uses simplified assumptions. Real grants may include special terms, refresh grants, early exercise rights, repurchase rules, or different tax treatment. Startup valuations can change quickly. Future financing can change ownership and share counts. Exit timing also matters. Use this tool as a planning guide, not legal or tax advice. It works best when paired with your offer letter, cap table context, and a discussion with the company. Good planning starts with better assumptions and honest comparisons.
Fully diluted shares include common stock, preferred stock, option pools, and other securities that can become shares. It gives a clearer ownership denominator.
Dilution reduces your ownership percentage when new shares are issued. Your grant size may stay fixed, but your share of the company usually becomes smaller.
The strike price is the amount you pay per option share to exercise your grant. Lower strike prices can improve potential upside if exit value rises.
Vesting determines how many shares you actually earn over time. A large grant sounds attractive, but unvested shares may never become yours.
No. It gives an estimate based on your assumptions. Real payouts depend on company performance, future financing, taxes, and the final exit structure.
Yes. Gross value can look impressive, but taxes and exercise cost reduce take-home value. Net estimates are better for practical career decisions.
Yes. Enter each offer separately and compare ownership, vested value, dilution impact, and breakeven valuation. That makes the tradeoffs easier to see.
No. A larger grant can still represent lower ownership if the company has many fully diluted shares. Percentage ownership and strike price matter too.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.