Safe Calculator for Seed Technical Founder

Understanding SAFE Agreements

A SAFE (Simple Agreement for Future Equity) is one of the most popular instruments for early-stage fundraising. Understanding how SAFEs convert into equity at your next priced round is critical for founders who want to maintain control of their cap table.

How SAFE Conversion Works

When a priced round occurs, your SAFE converts based on either the valuation cap or the discount rate, whichever gives the investor a better price. Our calculator models these scenarios so you can see exactly how much dilution to expect.

How to Use the Safe Calculator

1. Enter your SAFE terms including valuation cap and discount rate
2. Set your expected Series A valuation and round size
3. Review the conversion scenarios and resulting ownership percentages
4. Compare different negotiation outcomes side by side

When to Use This Calculator

• You are about to sign a SAFE and want to understand dilution at different future valuations
• You have multiple SAFEs outstanding and need to model how they stack at conversion
• You are preparing for a priced round and want to preview your post-conversion cap table
• You want to compare the impact of different valuation caps or discount rates before negotiating

Key Metrics and Formulas

SAFE conversion hinges on two numbers: the valuation cap and the discount rate. The conversion price is the lower of (valuation cap / fully diluted shares) or (price per share * (1 - discount rate)). Post-money SAFEs fix the denominator at the time of signing, making dilution predictable. Pre-money SAFEs leave the denominator open until the priced round, which can surprise founders if they raise additional SAFEs. Our calculator models both structures and shows the effective price per share, the number of shares issued, and the resulting ownership percentages for founders and investors.

Common Mistakes to Avoid

• Ignoring how multiple SAFEs stack: Each SAFE dilutes founders independently, and the cumulative effect is often larger than expected
• Confusing pre-money and post-money SAFEs: Post-money SAFEs include the option pool and all other SAFEs in the denominator, which changes the math significantly
• Setting the valuation cap too low to close quickly: A low cap means more dilution at conversion, and you cannot renegotiate after signing
• Forgetting that SAFEs do not have maturity dates: Unlike convertible notes, SAFEs only convert at a priced round, which means investors wait indefinitely