Data Size Converter — MB, GB, TB & Binary Units

Convert storage units with an explicit SI vs IEC toggle so marketing terabytes and OS “gigabytes” stop fighting in your head—then copy a one-line summary for tickets or specs.

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By Muhammad Abdullah Rauf · Founder, EverydayTools.proUpdated 2026-05-22

What is a data size converter?

A data size converter translates amounts between bits, bytes, and prefixed units—using either decimal (SI, powers of 1000) or binary (IEC, powers of 1024) steps—so file sizes, backups, and hardware labels can be compared without hand-calculator errors.

Digital storage is counted in bytes. Prefixes group large counts: SI uses kilo = 1000, mega = 10⁶, giga = 10⁹, and so on—the system printed on many SSD boxes and cloud invoices. IEC binary prefixes (KiB, MiB, GiB, TiB) use powers of 1024 (2¹⁰), which matches a lot of software internals and RAM sizing.

The famous 'missing gigabytes' on a new drive are usually not corruption: the label and the OS are often using different counting bases. Networking speeds add another wrinkle—Mbps is bits per second, while file managers show MB/s (bytes per second), an 8× difference.

  • Toggle SI vs IEC in this tool to match the document you are reading.
  • Use the quick presets for common MB→GB and GiB-style checks.
  • Pair with a speed converter when you need to relate line rate to transfer time.

Pick the same convention as your source: decimal for many product labels, binary for much OS and developer math—and never mix Mbps with MB/s without dividing by eight.

Quick answers

Concise answers for common searches — definitions, steps, and comparisons.

Is the data converter private?

Yes. Conversions run entirely in your browser. Values you enter are not uploaded to EverydayTools servers.

When should I use SI vs IEC?

Use SI (KB, MB, GB with 1000 steps) for SSD labels and many cloud bills. Use IEC (KiB, MiB, GiB with 1024 steps) for RAM sizing and much OS or developer math.

Quick Mbps to MB/s rule?

Divide megabits per second (Mbps) by 8 to estimate megabytes per second (MB/s). A 100 Mbps line is roughly 12.5 MB/s before protocol overhead.

How conversions are computed

Every unit is converted through bytes: value × (unit’s bytes per 1) ÷ (target unit’s bytes per 1). SI uses 10³ⁿ; IEC uses 2¹⁰ⁿ from the byte upward.

Formula

bytes = amount × factor(unit); targetAmount = bytes ÷ factor(target). Bit uses factor ⅛ byte.

Assumptions

  • Non-negative amounts only
  • No filesystem overhead or compression

Limitations

  • Does not model sparse files, RAID parity, or vendor reservation blocks

How to use Data Size Converter — MB, GB, TB & Binary Units

  1. Choose decimal or binary

    Use the SI (1000) toggle for label-style megabytes and gigabytes, or IEC (1024) for kibibytes and mebibytes—the units in the lists change to match.

  2. Enter a size

    Type a non-negative number; commas are ignored. All listed units update together.

  3. Pick from and to

    Tap a unit under From or To, or use Swap to flip the pair. The highlighted row shows the conversion factor.

  4. Copy or share

    Copy Result grabs a one-line summary including which convention you used. Share appears on supported devices.

Data Size Converter — MB, GB, TB & Binary Units examples

SSD label vs OS 'GB'

Input

1 TB (decimal, SI) capacity

Output

≈ 931 GiB shown in many OS summaries

1×10¹² bytes ÷ 2³⁰ ≈ 931.32. The bytes are the same; the divisor changed.

Photo archive in GiB

Input

12,000 MiB of JPEGs

Output

≈ 11.71875 GiB

12,000 × 2²⁰ ÷ 2³⁰ = 12,000 ÷ 1024 GiB—pure binary stepping.

Who uses Data Size Converter — MB, GB, TB & Binary Units?

Common real-world scenarios where this tool saves time.

Backup sizing

Turn '500 GB incremental' into TiB or bytes so tape and object-storage tiers line up with vendor quotes.

Media workflows

Estimate how many hours of 4K footage fit a drive when editors mix GB/hour rules with binary project disks.

Teaching networking

Show Mbps vs MB/s and why a 100 Mbps link does not move 100 megabytes per second.

Reference tables

Typical file and media sizes (order-of-magnitude)

Real files vary with quality and compression—use as intuition, not guarantees.

WhatRough size
MP3 song (3–4 min)3–10 MB
Smartphone JPEG2–8 MB
Raw photo (24 MP)15–40 MB
1080p movie (compressed)4–8 GB
4K movie (compressed)40–100 GB
AAA game install50–150 GB
Mobile OS update3–6 GB

Streaming bitrate changes these numbers; always check your source file or export settings.

Download time sketch (ideal, no overhead)

Time ≈ file size in bits ÷ line rate in bits per second.

File100 Mbps link1 Gbps link
1 GB (8×10⁹ bits)~80 s~8 s
10 GB~800 s (~13 min)~80 s
100 GB~8,000 s (~2.2 h)~800 s

Divide Mbps by 8 for MB/s. TCP, Wi-Fi, and disk writes usually reduce real throughput.

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Frequently Asked Questions

What is the difference between MB and MiB?

MB (megabyte) usually means 10⁶ bytes (1,000,000) in the SI decimal system—the convention many drive labels and cloud bills use. MiB (mebibyte) is exactly 2²⁰ bytes (1,048,576) in the IEC binary system. The ratio is about 4.86% at the megabyte scale and grows with each step, which is why mixing them stacks error.

Should I use 1000 or 1024 between KB, MB, and GB?

Use 1000 (SI) when you want to match storage marketing, many cloud SKUs, and scientific SI prefixes. Use 1024 (IEC: KiB, MiB, GiB) when you want to match how much software and OS internals count RAM and some filesystem math. This tool has a toggle so you can see both without guessing.

Why does my 1 TB SSD show as ~931 GB in Windows?

The label TB is usually 10¹² bytes (decimal). Windows historically shows “GB” using binary gibibytes (dividing by 2³⁰). 1,000,000,000,000 ÷ 1,073,741,824 ≈ 931.3—that is the same capacity expressed in a different counting base, not missing space from formatting alone.

How do I convert Mbps to MB/s?

Megabits per second (Mbps) counts bits; megabytes per second (MB/s) counts bytes. Divide Mbps by 8 for a first-order MB/s estimate. Example: 100 Mbps ≈ 12.5 MB/s before protocol overhead. Real downloads are often a bit lower than the ideal line rate.

How many GB in a TB?

In decimal SI: 1 TB = 1,000 GB. In binary IEC: 1 TiB = 1,024 GiB. Headlines and storefronts usually mean decimal TB; OS panels may show GiB while saying “GB.” Pick the toggle that matches the document you are reconciling.

Is a kilobyte 1000 or 1024 bytes?

Historically both were called “kilobyte,” which caused decades of confusion. Modern practice: KB = 1000 bytes (SI), KiB = 1024 bytes (IEC). If a spec does not say which, check context—RAM and many developer tools lean binary; consumer storage labels lean decimal.

Are my inputs uploaded?

No. All math runs in your browser; nothing you type is sent to our servers.

Privacy, accuracy, and trust

Privacy

Inputs stay in your browser; nothing is uploaded for conversion.

Accuracy

Factors are exact powers of 1000 or 1024. Real disks also reserve space for formatting and firmware; this tool converts ideal capacities only.

Part of Unit Converters

More free tools for the same workflow.

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Reviewed by EverydayTools Editorial Team on 2026-05-22.