Post-Money Valuation
A company's valuation immediately after new investment, equal to pre-money plus the amount raised.
Post-money valuation is pre-money plus the new investment. It is the number that determines what percentage the new investor owns: investment divided by post-money.
Because ownership is calculated against post-money, it is the figure founders should anchor on. Every conversation about dilution is really a conversation about post-money.
Post-money SAFEs made this more important. When several SAFEs each fix a post-money ownership percentage, their dilution stacks onto the founders rather than onto each other.