Check Size Calculator

Your check size should be driven by three constraints: your fund size (each check should be 2-5% of total fund), your target ownership (typically 5-15% at seed), and the number of investments you plan to make (20-30 for diversification). Start with your thesis — what stage and valuation range you're targeting — then work backward. A $10M fund writing $250K checks can make 25 investments with 40% reserves, giving solid diversification for power law math.

Most experienced fund managers maintain a consistent initial check size within a narrow range (e.g., $200K-$300K) rather than varying dramatically deal to deal. Consistency signals discipline to LPs and keeps your portfolio construction math clean. However, some funds use a tiered approach — a standard check for most deals and a larger 'high conviction' check (1.5-2x the standard) for 2-3 deals per fund where they have exceptional confidence.

Most institutional seed funds reserve 40-60% of their capital for follow-on investments. This means on a $10M fund, only $4-6M goes to initial checks, with the rest reserved for doubling down on winners in subsequent rounds. Under-reserving (below 30%) means you can't exercise pro-rata rights in your best companies. Over-reserving (above 70%) means too few initial bets for adequate portfolio diversification.

At pre-seed valuations ($3-8M), a $100K-$250K check gets you 2-5% ownership. At seed ($8-20M), you need $250K-$2M for 5-15% ownership. At Series A ($20-60M), lead investors typically write $3-10M for 15-20% ownership. For fund-returning math to work, you generally need at least 5% ownership — otherwise even a massive exit won't meaningfully impact your fund's overall returns.