Byte Calculator
Convert data sizes between bits, bytes, KB, MB, GB, TB and up to YB, including binary units (KiB, MiB, GiB, TiB) and bit units (kbit, Mbit, Gbit). Shows side by side why a 1 TB drive appears as about 931 GB in some operating systems, and how megabits relate to megabytes.
What does the Byte Calculator do?
It converts an amount of digital data into 26 units at once. Three families are listed: decimal byte units (kB, MB, GB ... YB, powers of 1,000), bit units (bit, kbit, Mbit ... Ybit) and binary byte units (KiB, MiB, GiB ... YiB, powers of 1,024). Seeing them together makes the decimal / binary difference and the 8-bits-per-byte factor obvious. All math is done in your browser.
How to use
- Enter a size in any row, e.g. 1 in Terabyte. The Gibibyte row shows ≈ 931.323 GiB and Tebibyte ≈ 0.909495 TiB.
- Use rounding digits to control the decimals shown.
- Turn on Description to see each unit's definition, Ratio to compare each unit with the top row, and Separators for thousands separators.
- Drag rows by the handle to reorder. The first row is the (base unit) used for ratios.
- Press Up / Down in a row to add or subtract 1 of that unit.
Decimal vs binary units
| Decimal (SI) | Bytes | Binary (IEC) | Bytes |
|---|---|---|---|
| 1 kB | 1,000 | 1 KiB | 1,024 |
| 1 MB | 1,000,000 | 1 MiB | 1,048,576 |
| 1 GB | 10⁹ | 1 GiB | 1,073,741,824 |
| 1 TB | 10¹² | 1 TiB | 1,099,511,627,776 |
Storage makers use decimal units, while some operating systems (Windows, for example) measure in binary units but label them "KB", "MB" and "GB". That is why a 1 TB drive is reported as about 931 GB there.
Conversion examples
- 1 byte = 8 bits
- 1 GB ≈ 0.931323 GiB
- 100 Mbit = 12.5 MB, so a 100 Mbps connection transfers at most 12.5 MB per second
- 1 Gbit = 125 MB
Features
- 26 units: decimal bytes, bits and binary bytes from bit to yottabyte
- Convert from any row, in both directions
- Exact factors with 40-digit precision, even for yottabytes and yobibytes
- Adjustable rounding, separators, ratios and unit descriptions
- Unit order, value and options are kept in this browser
FAQ
Is 1 KB 1,000 or 1,024 bytes?
In this tool, kB / MB / GB are decimal (1,000-based) and KiB / MiB / GiB are binary (1,024-based), following the SI and IEC standards. If a program says "KB" but means 1,024 bytes, use the KiB row.
Can I convert Mbps to MB/s?
Yes, the ratio is the same: enter the number in Megabit and read Megabyte to get MB per second. The tool itself does not have per-second units.
Is anything uploaded?
No. The tool only works with numbers you type and runs entirely in your browser.