Startup Dilution Calculator
See how a round, option pool and SAFE stack dilute founder ownership before you sign.
Your dilution will appear here
The form starts with a sample seed round. Calculate as-is, or enter your own cap table first.
Dilution is not only the new investor's percentage.
Option pools and converting SAFEs can move more ownership than founders expect.
Order matters
Pre-money pool increases are usually paid by existing holders before the new money comes in.
SAFEs are not free
A capped SAFE converts into real ownership at the priced round.
Scenarios create leverage
Small valuation changes can move founder ownership by meaningful points.
How dilution is estimated
The model normalizes the current cap table, converts SAFEs, applies the option pool and issues new investor ownership.
This is a fast modelling tool, not legal advice.
Real documents can change conversion mechanics; confirm before signing.
Dilution mistakes
Only looking at the headline round
New money dilution is just one line in the after table.
Treating the pool as neutral
A pre-money pool is a founder cost unless negotiated otherwise.
Ignoring old SAFEs
They may have been signed months ago, but they convert now.
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Questions founders ask
How much dilution is normal in a round?
Most priced rounds land around 15-25% dilution for new money before pool and SAFEs. Pool increases and converting SAFEs can make total founder dilution higher.
What is the difference between a pre- and post-money pool?
A pre-money pool is created before investment, so existing holders absorb it. A post-money pool spreads the cost across everyone, including the new investor.
Does this handle multiple SAFEs?
This calculator models converting SAFEs as one combined amount and cap for a fast estimate. Use the SAFE calculator for one instrument in detail.