Who absorbs dilution when stacking multiple Post-Money SAFEs?

Founders absorb 100% of the dilution from each new post-money SAFE; previously issued post-money SAFEs are completely protected from dilution by other SAFEs.

Updated: August 2026 • Verified v1.2

Pre-Money vs Post-Money SAFE Dilution Stack Calculator

Finance & MathNew

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Post_Safe_Pct = Investment / Valuation_Cap; Founder_Equity = (100% - Sum_Safe_Pcts) * (1 - SeriesA_Pct - OptionPool_Pct)

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Understanding Your Results

Models multiple SAFE tranches with distinct investments and valuation caps, calculates conversion into preferred stock at Series A alongside option pool expansion, and compares post-round founder equity ownership under both Pre-Money and Post-Money frameworks.

Practical Guidance & Next Steps

With Post-Money SAFEs, each investor owns a guaranteed fixed percentage (Investment / Cap) of the pre-Series-A company, meaning founders bear 100% of the dilution from every subsequent SAFE raised.

What is this?

A capitalization table modeling tool for startup founders to visualize dilution when stacking multiple SAFE notes prior to a priced round.

How does it work?

1. Add SAFE tranches with check sizes and valuation caps. 2. Enter Series A pre-money valuation, new investment, and option pool percentage. 3. Compare founder equity ownership and investor cap tables under Pre-Money vs Post-Money mechanics.

Why use it?

Protects startup founders from unexpected equity dilution when raising successive seed checks on convertible SAFEs.

Technical Scope & Calculation Limitations

Y Combinator SAFE standard post-money and legacy pre-money models.

Frequently Asked Questions

Post-money SAFEs provide immediate ownership certainty to investors by fixing their percentage upfront, avoiding the complex circular math of pre-money SAFEs.

Windows Desktop & Widget Options