Digital Data Converter
Convert between bits, bytes, and everything up to petabytes — with correct binary and decimal handling.
The unit confusion that trips everyone up
Digital data has a persistent ambiguity baked into it: the same abbreviation can mean two different things depending on who's using it. When your operating system reports a file as "1 GB," it typically means 1,073,741,824 bytes (2³⁰). When a hard drive manufacturer labels a product "1 TB," they mean exactly 1,000,000,000,000 bytes. That gap — about 7% at the gigabyte scale, growing wider as you move to terabytes — is where the confusion lives.
This converter handles both standards. Understanding which one applies to your situation is what the sections below are for.
Binary (IEC standard)
Powers of 2 — 1 KB = 1,024 bytes
Used by: Operating systems (Windows, Linux, macOS), RAM specs, file system reporting
KiB, MiB, GiB, TiB
Decimal (SI standard)
Powers of 10 — 1 KB = 1,000 bytes
Used by: Hard drives, SSDs, USB drives, internet bandwidth (ISPs)
KB, MB, GB, TB
Who uses it — and the specific problems it solves
Developers & DevOps Engineers
Cloud providers price storage and data transfer in gigabytes, but their SDKs and monitoring tools often report in bytes or mebibytes. When an AWS Lambda function returns a memory usage of 67,108,864 bytes, converting that mentally to 64 MiB (not 67.1 MB) matters when you're debugging against a 128 MiB limit. The difference between binary and decimal is not rounding noise at this scale.
Network & Infrastructure Engineers
ISPs advertise speeds in megabits per second (Mbps) — not megabytes. A 100 Mbps plan delivers roughly 12.5 MB/s of actual throughput, not 100 MB/s. This distinction is misunderstood often enough that it generates support tickets. If you're provisioning bandwidth or calculating how long a backup transfer will take, this conversion is foundational.
System Administrators
Disk capacity discrepancies are one of the most common sources of confusion in storage provisioning. A 2 TB drive formatted on a Linux system might show ~1.82 TiB available — it hasn't lost space, it's just that the OS reports in binary units while the drive was labeled in decimal. Understanding the gap prevents incorrect capacity planning.
Content Creators & Video Editors
Raw video files are large and the numbers matter for storage planning. A 10-bit 4K RAW file might run 2.5 GB per minute. Knowing that a 2-hour project produces roughly 300 GB of footage — and translating that to how many terabytes of working storage you need — requires quick, accurate conversion.
Everyday Users & Students
Email attachments have size limits in MB. Mobile data plans are sold in GB. Game downloads are measured in GiB by some platforms and GB by others. These conversions come up constantly, and being off by even 7–10% can mean the difference between a file fitting somewhere and not.
Real-world examples
Concrete numbers help anchor the scale. Here are conversions that come up in actual technical work:
| Scenario | Input | Output |
|---|---|---|
| 100 Mbps internet plan | 100 Mbps | 12.5 MB/s |
| AWS Lambda default limit | 128 MiB | 134,217,728 bytes |
| Blu-ray disc capacity | 50 GB | 46.57 GiB |
| 1-minute 4K ProRes RAW | ~12 Gbps | ~90 GB/min |
| Ethernet frame max size | 1,500 bytes | 11.72 Kib |
| Typical SSD (decimal label) | 1 TB | ≈ 931 GiB |
Tips for accurate results
Bandwidth is always in bits
Every ISP and networking spec quotes speeds in bits per second (bps, Kbps, Mbps, Gbps). Storage is in bytes. When calculating download times, divide your Mbps by 8 to get MB/s — that's your real-world file transfer speed.
Hard drives lie — sort of
Drive manufacturers use decimal GB (1 GB = 1,000,000,000 bytes). Your OS uses binary GiB (1 GiB = 1,073,741,824 bytes). A 500 GB drive shows up as ~465 GiB in Windows or Linux. No space is missing — it's just labeling.
MiB vs MB is not a typo
The IEC introduced kibibyte (KiB), mebibyte (MiB), gibibyte (GiB) in 1998 specifically to disambiguate binary from decimal. Linux, Java, and most developer tooling use MiB/GiB. Consumer software often uses MB/GB to mean either, depending on context.
Calculating transfer time
Divide file size in megabytes by your speed in MB/s. A 4 GB file (4,096 MB) over a 100 Mbps connection (~12.5 MB/s) takes about 328 seconds — just under 5.5 minutes. Real-world overhead adds 10–20% on top.
Quick reference — the full scale
How the units stack up, in both binary and decimal, from smallest to largest:
| Name | Symbol | Decimal (bytes) |
|---|---|---|
| Bit | b | 0.125 |
| Byte | B | 1 |
| Kilobyte | KB | 1,000 |
| Megabyte | MB | 1,000,000 |
| Gigabyte | GB | 1,000,000,000 |
| Terabyte | TB | 1,000,000,000,000 |
| Petabyte | PB | 1,000,000,000,000,000 |
Limitations to keep in mind
- —Transfer time calculations are theoretical maximums. Real throughput is reduced by protocol overhead, latency, server throttling, and network congestion — expect 70–85% of the raw figure in practice.
- —This tool converts data size units, not data rates over time. If you need to model sustained bandwidth or IOPS for storage systems, a dedicated capacity planning tool is more appropriate.
- —RAID and redundancy are not factored in. A 4-drive RAID 10 array using 4 × 2 TB drives has 4 TB usable — not 8 TB. Usable storage depends on the RAID level, not just raw drive capacity.
- —Compression ratios are context-dependent. A 10 GB ZIP archive might compress to 2 GB or 9.5 GB depending on the content. This tool works with raw, uncompressed sizes.
Frequently asked questions
What's the difference between a bit and a byte?
A bit is a single binary value — either 0 or 1. A byte is 8 bits grouped together, which is the smallest addressable unit of memory in most computer architectures. Network speeds are quoted in bits (Mbps, Gbps) while file sizes and storage are quoted in bytes (MB, GB). This is why downloading a file from a 100 Mbps connection gives you ~12.5 MB/s, not 100 MB/s.
Is 1 KB equal to 1,000 or 1,024 bytes?
Both definitions exist and are in active use, which is the root of most confusion. Hard drive manufacturers use 1 KB = 1,000 bytes (decimal/SI). Operating systems traditionally use 1 KB = 1,024 bytes (binary). The IEC formalized the binary version as 'kibibyte' (KiB) in 1998, but the KB abbreviation is still widely used for both. This converter lets you work in either standard.
Why does my 1 TB hard drive show less space in Windows?
Your drive was labeled using decimal gigabytes (1 TB = 1,000,000,000,000 bytes). Windows reports storage in binary gibibytes. Dividing 1,000,000,000,000 by 1,073,741,824 (bytes per GiB) gives you about 931 GiB — which Windows displays as '931 GB.' No storage is lost; it's purely a labeling difference between the manufacturer and the OS.
How do I calculate how long a file download will take?
Divide the file size in megabytes by your connection speed in megabytes per second. First, convert your ISP speed from Mbps to MB/s by dividing by 8. So a 100 Mbps connection = 12.5 MB/s. A 500 MB file at 12.5 MB/s takes 40 seconds. Real-world transfers are typically 15–25% slower due to protocol overhead and network conditions.
What's a petabyte, and when would I encounter one?
A petabyte is 1,000 terabytes (decimal) or 1,024 TiB (binary) — a scale most individuals never deal with directly. Large cloud providers, data centers, and hyperscalers operate at petabyte scale. Facebook was reportedly processing several petabytes of data per day as early as 2014. For context, 1 PB could hold roughly 200,000 standard Blu-ray discs.