2¹⁰ ≈ 10³

Every 10 bits multiplies by ~1,000 — kibi and kilo differ by just 2.4%.

Why it works

2¹⁰ = 1,024. So 2²⁰ ≈ a million, 2³⁰ ≈ a billion — powers of two estimated in your head to within a few percent.

Do it exactly

Estimate with the rule, then check it against the calculator that models it properly.

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