The Math Behind Your Angel Check Size
Originally sent to Play Money subscribers · March 2026
Part of our ongoing Tuesday series on how angel investing deal mechanics actually work — check sizing, diversification math, and the frameworks behind every portfolio.
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💎 Every Angel 101 I've run has the same moment.
I pull up my portfolio. About 50 checks. Then I tell the room my check size: $1,500.
Silence. Eyes go wide. And then something changes. Because they realize: you can be a real angel without writing a massive check.
You just need the math.
-- C2K
Figuring out your check size
I see 2 groups of people get stuck on check size, and they're stuck in opposite directions.
The first group writes one check that's too big, panics when they realize they can't diversify at that size, and never writes another. More men make this mistake.
The second group sits on the sidelines, convinced their check won't be big enough to matter. More women make this one.
"Just invest what you're comfortable losing" is the most common, and most lazy, useless guidance that gets shared.
Both groups are missing the same thing: a framework.
The math is simple. Standard financial planning puts alternative assets at 25-35% of net worth. Angel investing sits at 5-7% of that. Take that number, divide by 30, and spread it over 3-5 years.
That's your check size. And yes, it really is that simple.
But why 30?
The AngelList data science team ran the numbers. The single biggest predictor of angel returns wasn't sector, geography, or founder pedigree. It was the number of bets.
Under 30, you're running independent bets where one bad one can wreck you. At 30+, diversification math actually works in your favor.
Yeah this graph is SUPER geeky. Sorry not sorry.
The amount isn't what makes you credible.
How you show up after the check does.
One of Play Money's angels wrote a $2,500 check to a medical startup last summer. Exited founder. Kept his check baby-sized because he believed in diversification. Then he helped that founder find her new CEO candidate.
One of her most impactful investors came in with what I'd call a baby check.
Small checks, big change.
Once you have the baseline, you can decide when and why to deviate. My biggest check ever is roughly 8x my normal size, in an endometriosis biotech I partly funded from my philanthropy budget. Impact with upside.
But you need the baseline before you can make that call intentionally.
"Yikes! 30 feels like a big commitment."
You also don't have to commit to 30 to start. Write 1 or 2. See if you like it. If you don't, small adventure, a little learning, move on. If you do, you've already set yourself up right.
On Play Money, it's always free to lurk and learn. New deal every week, no pressure.
There's actual math here. The only reason most angels don't use it is that nobody taught it to them at the start.
Now you have it. Loud and proud baby check writer, ride or die.
-- C2K
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Play Money makes angel investing accessible by helping everyday angels build diversified startup portfolios without turning it into a full-time job.
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