Guides · Explainer
Mbps vs. MBps: internet speeds explained
Your 100 Mbps plan downloading at 12.5 MB/s is correct, not broken. The one-letter difference that confuses everyone, explained.
Jean Gilles · Founder & editor
Published May 15, 2026 · Updated Jul 14, 2026 · 3 min read
A speed test result on a laptop screen. Click to edit this caption.
The short answer
Internet plans are sold in megabits per second (Mbps); file sizes and download managers use megabytes per second (MBps). There are 8 bits in a byte, so a 100 Mbps plan downloads at about 12.5 MB per second. Same speed, different unit.
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Now that the units make sense, figure out what speed you actually need.
More on this topic
Founder & editor
Jean founded ShopHighSpeed after trying to find one straight answer about business internet in his own town. He has been a Comcast and Verizon Fios customer, and builds the site’s rankings from the availability data providers file with the FCC rather than from provider marketing.