A customer opens a ticket: the new 2 TB disk "only has 1.8 TB". A VM template asks for disk size in GiB while the storage array reports TB. A backup quota is 500 GB, but du -h shows 466G. None of these are errors — they are the same byte counts expressed with two different prefix systems.
The Data Storage Converter converts sizes between bits, bytes, decimal units (kB, MB, GB, TB, PB) and binary units (KiB, MiB, GiB, TiB, PiB), exactly, and shows the decimal and binary interpretation side by side so the difference is obvious. It runs in your browser.
What is the Data Storage Converter?
In simple terms
You enter a size and its unit; the tool shows it in every storage unit and in two comparison cards: one in decimal units (as drive makers and network gear count) and one in binary units (as RAM and many operating systems count).
Technical background
A byte is 8 bits. Multiples come in two families:
| Decimal (SI) | Bytes | Binary (IEC) | Bytes | Binary is larger by |
|---|---|---|---|---|
| kB (kilobyte) | 1,000 | KiB (kibibyte) | 1,024 | 2.4% |
| MB (megabyte) | 1,000,000 | MiB (mebibyte) | 1,048,576 | 4.86% |
| GB (gigabyte) | 10⁹ | GiB (gibibyte) | 1,073,741,824 | 7.37% |
| TB (terabyte) | 10¹² | TiB (tebibyte) | 1,099,511,627,776 | 9.95% |
| PB (petabyte) | 10¹⁵ | PiB (pebibyte) | 1,125,899,906,842,624 | 12.59% |
Storage vendors label capacity in decimal units. Memory is built in powers of two. Operating systems differ: Windows Explorer divides by 1024 but prints "GB"; macOS has used decimal units since 10.6; Linux tools vary (df -h uses powers of 1024 with a single letter, df -H powers of 1000). The binary prefixes were introduced by the IEC to remove the ambiguity, but labels like "GB" still often mean GiB.
Why use the Data Storage Converter?
- Explain "missing" capacity to users and customers with exact numbers.
- Size VMs, LUNs and quotas when one system wants GiB and another TB.
- Avoid compounding errors. The converter uses exact fractions, so
1 GiB = 1 073 741 824 Band0.1 GB = 100 MBwithout floating-point noise. - See both interpretations at once in the decimal versus binary cards, instead of guessing which one a tool used.
Who should use it?
Storage and system administrators, help-desk staff answering capacity questions, DevOps engineers writing Terraform or Kubernetes resource requests (where Gi and G differ), and buyers comparing drive and memory specifications. If you plan arrays, continue with the RAID Calculator, which accepts disk sizes in both unit families.
How the Data Storage Converter works
All arithmetic runs in your browser.
- Parsing. The size is read as an exact decimal. Spaces, underscores and apostrophes are ignored; a single comma counts as a decimal comma; with a dot present, commas are thousands separators. Negative sizes are rejected ("Data storage cannot be negative.").
- Base unit. Every unit has an exact factor in bits: bit = 1, B = 8, kB = 8,000, MB = 8 × 10⁶ … PB = 8 × 10¹⁵, KiB = 8 × 1024 … PiB = 8 × 1024⁵.
- Conversion.
value × factor(from) ÷ factor(to), on BigInt fractions. Results show up to 10 decimal places with grouped thousands; the main result notes when it was rounded. - Decimal vs binary cards. The size is converted to bits, then the tool picks the largest unit in each family that keeps the value at 1 or above, and shows it with up to 4 decimal places, plus the exact byte count (up to 3 decimals).
Units offered in the From and To selects are grouped as Bits & bytes (bit, B), Decimal (SI, ×1000) (kB, MB, GB, TB, PB) and Binary (IEC, ×1024) (KiB, MiB, GiB, TiB, PiB). The alias "KB" is mapped to the decimal kB.
How to use the NetTools.tech Data Storage Converter
- Open the Data Storage Converter.
- Enter the Size (default
1). - Choose From and To (default TB → GiB). Results update immediately.
- Click an example: 1 TB → GiB (the "931 GB" question), 4.7 GB → GiB (a single-layer DVD) or 16 GiB → GB (a RAM module).
- Read the Decimal vs binary cards and the In every unit list.
- Swap the units with the swap button (the result becomes the new input) or Reset.
- Export with CSV, JSON, Copy all or Print; the export includes every unit with its prefix system (SI or IEC).
Understanding the results
| Result | Meaning | What to look for |
|---|---|---|
| Main result | Size in the To unit with the full equation | "(rounded to 10 decimal places)" when the exact value is longer |
| Decimal (SI) card | Most readable decimal unit, e.g. 1 TB | What a drive label or a decimal-reporting OS shows |
| Binary (IEC) card | Most readable binary unit, e.g. 931.3226 GiB | What Windows and many Linux tools show, often labelled "GB" |
| Bytes line in cards | Exact byte count | Identical in both cards — only the unit changes |
| In every unit | All 12 units, target highlighted | Use the row matching the tool you compare with |
| Note | 1 byte = 8 bits; SI ×1000, IEC ×1024 | Reminder of the definitions used |
Example: why a 2 TB disk shows 1.82 "TB"
Enter 2 TB and convert to TiB:
2 TB = 1.8189894035 TiB (rounded to 10 decimal places)
Decimal (SI) 2 TB 2 000 000 000 000 bytes
Binary (IEC) 1.819 TiB 2 000 000 000 000 bytesThe byte count is the same; the operating system divides by 1024⁴ and shows "1.81 TB". In the In every unit list, the same disk is 1 862.645149231 GiB and 1 907 348.6328125 MiB.
A second case from the examples: 16 GiB → GB is exactly 17.179869184 GB (17 179 869 184 bytes). And the 500 GB backup quota from the introduction is 465.6612873077 GiB, which du -h rounds to 466G.
Common use cases
- Answering "where did my disk space go?" tickets with exact figures.
- Converting VM disk sizes between hypervisor (often GiB) and storage array (often TB) units.
- Writing Kubernetes requests:
Giis GiB,Gis GB. - Checking that a file fits on media or under an upload limit stated in MB or MiB.
- Translating memory sizes for documentation and procurement.
Troubleshooting
My operating system shows a smaller number than the converter's decimal card
Read the binary card instead — most likely your OS uses powers of 1024 with decimal labels. If it is still smaller, the rest is filesystem overhead, reserved blocks, a recovery partition or snapshots, which the converter cannot know about.
"Data storage cannot be negative"
Sizes must be zero or positive. Remove the minus sign.
The result is 1000 times too small
A single comma without a dot is read as a decimal comma: 1,024 becomes 1.024. Type 1024 or 1 024.
I need Mbit, not bits
The storage list has bit but no Mbit. Divide the bit value by 1,000,000, or use the Bits & Bytes Explainer, which shows storage values "As bits (SI)" in Mbit.
Common mistakes
- Assuming "GB" in an OS means 10⁹ bytes. Check which family the tool uses before comparing.
- Mixing bits and bytes.
Mbis megabit; storage is almost always quoted in bytes. - Believing larger drives "lose" more. The percentage gap grows with each prefix step (about 7.4% at giga, 9.9% at tera), but no bytes are lost.
- Using the converter for usable RAID or filesystem capacity. It converts units only; use the RAID Calculator and allow for filesystem overhead.
Limitations
- Pure unit conversion: it does not know your filesystem, block size, reserved space, compression or deduplication.
- Byte units stop at PB and PiB; there are no EB/EiB units.
- The decimal versus binary cards round to 4 decimal places; the full list rounds to 10.
- It cannot tell you which unit a given product label or tool actually uses — check its documentation.
Security & privacy
The converter runs locally in your browser and the sizes you enter are not transmitted. The page may send an anonymous usage counter (tool name and view or run, no values) unless your browser sends Global Privacy Control or Do Not Track. There is no reason to enter anything sensitive here.
Related tools
- Bits & Bytes Explainer — the background on bits, bytes and the two prefix families. Guide: Bits and bytes guide.
- Unit Converter — storage plus rates, time and timestamps. Guide: Unit Converter guide.
- RAID Calculator — usable array capacity in TB or TiB. Guide: RAID Calculator guide.
- Bandwidth Calculator — how long it takes to move a given size. Guide: Bandwidth Calculator guide.
- Category overview: Conversion & calculation tools.
Summary
The Data Storage Converter shows any size in decimal and binary units with exact arithmetic, which makes the classic "1 TB shows as 931 GB" gap easy to explain. The byte count never changes — only the divisor does. For real usable space, you still need to account for RAID, filesystems and reserved areas.
Frequently asked questions
Why does my new 1 TB drive show about 931 GB?
The drive holds 1,000,000,000,000 bytes, a decimal terabyte. Many operating systems divide by 1024³ and label the result GB although it is really GiB, and 10¹² ÷ 1024³ is about 931.32 GiB, so nothing is missing.
Is KB 1000 or 1024 bytes?
Strictly, kB is 1000 bytes and KiB is 1024 bytes. Older software often writes KB for 1024 bytes; this converter treats KB as the decimal kilobyte and offers KiB for the binary unit.
How many bytes are in a GiB?
One gibibyte is exactly 1,073,741,824 bytes (1024³). One gigabyte is 1,000,000,000 bytes, so a GiB is about 7.37% larger than a GB.
How much RAM is 16 GiB in GB?
16 GiB is 17,179,869,184 bytes, which is exactly 17.179869184 GB. Memory modules are sold in binary sizes even when the label says GB.
Can I convert to megabits with this tool?
The storage units include the bit but no kbit or Mbit multiples. Convert to bit and divide by one million, or use the Bits & Bytes Explainer, which shows a storage value as Mbit directly.
How big is the difference between TB and TiB?
One TiB is 1,099,511,627,776 bytes, about 9.95% more than one TB. Conversely, 1 TB is about 0.909 TiB, which is why the gap between label and display grows with drive size.