Honestly shocked by the real cost of a 401k loan | Finance Reviews

Grace Kelly · 2026-03-12T23:05:05.769393+00:00

Tbh, I was reading a review of Fidelity's retirement tools last night and saw that taking a loan from your 401k can cost you over $100k in lost growth over 20 years. I had no idea the hit was that big. Has anyone else run the numbers on this and decided it's never worth it?

taylor_moore5mo ago

Yeah, but the math is real... it's the lost compound interest that kills you.

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bailey.xena6mo ago

That "lost growth" math always seems a bit off to me.

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oscar_hernandez6mo ago

Over $100k in lost growth" is a crazy number to see written out like that!

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olivia_barnes975mo ago

Wait, didn't some finance guy do a whole breakdown on how those "lost growth" numbers assume you invest every single cent you save? Like, who actually does that? I mean, I saw one where they counted not buying a daily coffee as like a future million, but it ignored that most people would just spend that money on something else anyway. It feels like a scare tactic more than real math. Maybe it's just me but those big numbers never seem to match real life.

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