Startup Funding Ladder Calculator

Pre-seed ($0.25-$1M, friends/family/angels), Seed ($1-5M, seed VCs), Series A ($5-20M, sustainable growth), Series B ($20-50M, scale), Series C+ ($50M+, market expansion). Each round expects 3-5x growth from previous to justify higher valuation.

Raise if: capital intensive market, network effects (winner takes all), or you can deploy capital efficiently for >25% IRR. Bootstrap if: capital-efficient business, slow-and-steady fits the market, or you want to retain control. Most successful companies bootstrap longer than expected.

18-24 months runway minimum. Less = constant fundraising. More = excess dilution and lazy spending. Plan based on milestones to next round (achieve metrics that 3x valuation), not arbitrary amounts. Raise 50% more than minimum needed as safety buffer.

Per Carta data, the average founding team retains 15-20% by the time they reach Series C, after four rounds of dilution.

Each round dilutes the founder's remaining stake, not the original 100%. If you start with 80% and get diluted 20%, you keep 80% × 0.80 = 64%, not the 60% that simple subtraction would suggest.

The option pool is the block of shares set aside for employees and advisors. Refreshing it before a funding round dilutes founders on top of the round itself, typically by another 5 to 10%.

Pre-money valuation is the company's value before the new investment. Post-money includes the capital just raised: post-money = pre-money + raise. Dilution is always calculated against the post-money valuation.

This tool models formal equity rounds with set valuations. SAFEs and convertible notes add dilution at the moment of conversion, usually 3 to 8%, which you should add to the results manually.