Bits to bytes costs a factor of eight

Divide advertised Mbps by 8 for ideal MB/s — a 100 Mbps link is about 12.5 megabytes per second at full throttle.

Why it works

ISPs sell megabits; file sizes are megabytes. Protocol overhead and Wi-Fi mean real transfers run below that ideal.

Do it exactly

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

Open Data Transfer Time →

More in Computers

• 2¹⁰ ≈ 10³Every 10 bits multiplies by ~1,000 — kibi and kilo differ by just 2.4%.
• Each subnet bit halves the hostsEvery bit moved from host to network halves the addresses — a /24 has 254 usable.
• RAID is not a backupRAID protects against disk failure — deletion, ransomware and fat fingers replicate instantly.
• 3-2-1 backupsKeep 3 copies of anything that matters, on 2 different media, with 1 off-site.

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