Question 1

How do you calculate equity dilution?

Accepted Answer

Dilution percentage is the change in your ownership before and after a round. Formula: founder shares divided by total shares after the round, expressed as a percentage. The new total includes existing shares, any option pool top-up, and the new investor shares from the priced round. Stack rounds together and compounding kicks in: 80% retained per round, three times, leaves you at 51%, not 40%.

Question 2

How much equity should a founder give up in a seed round?

Accepted Answer

Carta's median seed round sold 18% of the company, raising $4.1M at a $24.3M post-money valuation, across more than 1,000 software rounds closed in the six months to July 2026. Carta reports that figure has been ticking down for months. Option pool top-ups sit on top of it, and so does any SAFE converting into the round, which is why effective seed-stage dilution usually lands well above the headline. The calculator above models the pool separately so you see the raise dilution and the pool dilution side by side.

Question 3

What is the option pool shuffle?

Accepted Answer

Most term sheets size the option pool as a percentage of post-money fully diluted, but place the pool pre-money. That means founders bear the entire pool dilution while investors keep the same ownership they paid for. The /option-pool page shows the dollar and percentage delta side by side. A 10% pool placed pre-money typically costs founders 3% to 8% more than the same pool placed post-money.

Question 4

What happens when SAFEs convert at a priced round?

Accepted Answer

Each SAFE converts at the lower of its valuation cap, the priced-round price discounted by its discount rate, or the priced-round price itself. Multiple SAFEs at low caps stack and convert together. Founders often raise three or four SAFEs without modeling conversion and are shocked to find their post-conversion ownership is 8 to 15 points lower than they expected. Use the /safe-dilution page to stack-test before signing the next term sheet.

Question 5

What is anti-dilution protection?

Accepted Answer

Anti-dilution provisions adjust earlier investors' conversion price in a down round so they keep more ownership than the math would otherwise give them. Full ratchet drops their price to the new low. Broad-based weighted average is the market standard and far less punitive. The /anti-dilution page lets you input a down round and compare founder ownership across all three mechanisms.

Question 6

How much equity do founders typically have after Series B?

Accepted Answer

Carta measures the median founding team at 21.8% of fully diluted shares on raising a Series B if the company is not AI, or 27.3% if it is. By Series C the median founding team holds 16.1%, which is less than the median employee option pool at 16.8%. These are measured cap tables, not compounded averages: chaining the round-dilution medians together (18%, 18%, then 12%) would predict about 59% at Series B, so the measured figures are between a third and a half of what the per-round numbers imply. The difference is pool top-ups, converting SAFEs and extra rounds inside a single stage label.

Stage	Median dilution	Median raise	Median post-money	Founders still own (measured)
Pre-seed	not published	—	—	—
Seed	18%	$4.1M	$24.3M	56%
Series A	18%	$14.4M	$80M	36%
Series B	12%	$25M	$191M	21.8–27.3%
Series C	under 10%	$40M	$391M	16.1%

Equity dilution calculator

Round-by-round dilution worksheet

The dilution formula

Dilution is multiplicative

Pre-money pool gotcha

What is normal at each stage

Equity dilution FAQ