Unit Converter
Convert storage sizes (GB vs GiB) and network speeds (Mbps vs MB/s), and estimate download times.
[local] Runs in your browser. Nothing you enter leaves your device.
Storage size
- B
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- KB
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- MB
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- GB
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- TB
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- PB
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- KiB
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- MiB
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- GiB
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- TiB
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- PiB
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Network speed
- bps
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- Kbps
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- Mbps
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- Gbps
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- B/s
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- KB/s
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- MB/s
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- GB/s
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- MiB/s
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Download time
- Best case
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- Realistic (~85% speed)
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How it works
Why a "1 TB" drive shows as 931 GB
There are two ways to count storage. Decimal units (KB, MB, GB, TB) go up in steps of 1,000, and drive makers use them. Binary units (KiB, MiB, GiB, TiB) go up in steps of 1,024, because computers count in powers of two.
Windows counts in binary but labels the result "GB". So a drive with 1,000,000,000,000 bytes (1 TB) shows as 1,000,000,000,000 ÷ 1,024³ ≈ 931 GB. Nothing is missing; it's the same number of bytes, measured with a different ruler. The gap grows with each step: about 2% at KB, 7% at GB, and 10% at TB.
Bits vs bytes
Network speeds are sold in bits per second (Mbps, with a small "b"), but files are measured in bytes (MB, with a big "B"). One byte is 8 bits, so divide by 8: a 1,000 Mbps (gigabit) connection downloads at most 125 MB/s.
Why downloads are slower than the math says
Every packet carries headers (TCP/IP, Ethernet, often TLS encryption), Wi-Fi loses speed to interference and distance, and the server on the other end may be the slowest link. Real transfers usually reach 80-95% of the line speed on a good wired connection, and often much less over Wi-Fi. The "realistic" estimate uses 85%.