Add new investment to the pre-money valuation and see the resulting ownership split.
Post-money valuation is a simple sum, but the option pool complicates ownership: it is normally carved out of the pre-money value, so existing holders bear it entirely. That is why effective pre-money is lower than the headline figure. The option pool shuffle is the least-understood term in a term sheet and routinely costs founders several percentage points more dilution than the headline valuation implies.
Post-Money Valuation
Post-money = pre-money + investment; ownership = investment ÷ post-money
Post-money = pre-money + investment; ownership = investment ÷ post-money Post-money valuation is a simple sum, but the option pool complicates ownership: it is normally carved out of the pre-money value, so existing holders bear it entirely. That is why effective pre-money is lower than the headline figure.
The option pool shuffle is the least-understood term in a term sheet and routinely costs founders several percentage points more dilution than the headline valuation implies.
This calculator takes 3 inputs: Pre-money valuation, Amount invested, New option pool created post-round. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.