What does not negotiating actually cost you?

The damage is not the gap you accepted. It is that every raise for the rest of your career compounds on a smaller base.

Not negotiating costs you

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How this is calculated

Both paths grow at the same annual raise rate. The only difference is the starting base.
Year n salary = base × (1 + raise)ⁿ
The cost is the sum of every year's difference — not just the gap itself, because each raise is a percentage of a smaller number.
Figures are in today's dollars, before tax, and ignore promotions and job changes.

Nothing you type leaves your device. No account, no tracking of your numbers, nothing stored.