Data Storage Converter - Bytes, KB, MB, GB, TB & GiB

About the Data Storage Converter

Phones, laptops, memory cards, cloud plans and backup drives all describe capacity in bytes and their multiples, but not always in the same way. A drive box says 1 TB, a computer reports 931 GB, a cloud plan offers 2 TiB, and a network spec quotes gigabits. Each of these can be converted exactly once you know which family of units it belongs to: decimal (steps of 1,000), binary (steps of 1,024) or bits (an eighth of a byte).

This data storage converter converts between fourteen units: bits, kilobits, megabits and gigabits; bytes, KB, MB, GB, TB and PB; and the binary KiB, MiB, GiB and TiB. It shows the result, the exact factor both ways, the size in every unit, and a feel for the amount — how many photos, songs or hours of video it holds.

How to Use the Data Storage Converter

Enter the size.

Choose the unit to convert from and to. Pick carefully between KB and KiB, GB and GiB, and bits and bytes — they are different amounts.

The result appears with the factor, the size in every unit and an everyday comparison.

The Three Families of Units

  bits      1 kbit = 1,000 bits      1 Mbit = 1,000,000 bits
            8 bits = 1 byte

  decimal   1 KB = 1,000 B    1 MB = 1,000 KB    1 GB = 1,000 MB
            1 TB = 1,000 GB   1 PB = 1,000 TB

  binary    1 KiB = 1,024 B   1 MiB = 1,024 KiB  1 GiB = 1,024 MiB
            1 TiB = 1,024 GiB

  result = value × (from-unit in bytes) ÷ (to-unit in bytes)

Step-by-Step Example

A 1 TB drive in GiB.

  To bytes:   1 TB = 1,000,000,000,000 B
  To GiB:     1,000,000,000,000 ÷ 1,073,741,824 = 931.323 GiB

So a 1 TB drive holds about 931.323 GiB — which is why a computer that counts in 1,024s shows it as "931 GB". It holds about 250,000 photos of 4 MB or 500 hours of HD video.

500 GB in TB is simply 500 ÷ 1,000 = 0.5 TB, or about 465.661 GiB.

100 megabits in megabytes is 100 ÷ 8 = 12.5 MB.

Why Two Systems Exist

Computers address memory in powers of two, so early programmers used "kilobyte" for 1,024 bytes because it was close to a thousand. As capacities grew, the gap widened: at the gigabyte level the binary figure is 7.4 percent larger, and at the terabyte nearly 10 percent. In 1998 the International Electrotechnical Commission introduced separate names — kibibyte, mebibyte, gibibyte, tebibyte — for the binary units, so that KB, MB and GB could keep their metric meanings.

Drive and memory-card makers, network equipment and most phones use decimal units. RAM is built in binary sizes. Operating systems differ: some show decimal units, some binary values with the old decimal names. The converter keeps the two apart so you can see exactly what each figure means.

Bits and Bytes

A bit is a single 0 or 1; a byte is 8 bits, enough to store one character of plain English text. Storage is measured in bytes, written with a capital B, while network speeds and some chip capacities are in bits, with a small b. A "512 Mbit" memory chip holds 64 MB, and a 100 megabit file transfer moves 12.5 MB.

How Much Fits

  1 page of plain text   about 2 KB
  1 phone photo          about 3–5 MB
  1 song (MP3)           about 5 MB
  1 hour of HD video     about 1.5–3 GB
  1 hour of 4K video     about 7–20 GB

These vary with quality, resolution and compression, so treat any "how many fit" figure as a guide rather than a promise.

Sizing a Backup

When planning a backup, add up what you want to keep in one unit, then allow room to grow. A family photo library of 60,000 pictures at 4 MB each is about 240 GB; add a few hundred hours of phone video and it can pass 1 TB. Backup software that keeps several versions of each file needs more space again, often one and a half to two times the size of the data. Because drives are sold in decimal terabytes but may be reported in binary units, a comfortable margin avoids a surprise when the drive shows less space than expected.

Cloud Storage Plans

Cloud services describe plans in GB or TB, and some count in binary units behind the scenes, so a 2 TB plan might hold 2 TiB, about 2.2 decimal terabytes, or exactly 2 decimal terabytes, depending on the provider. Their help pages usually say which. For most people the difference only matters close to the limit, but for large archives, video libraries or business data it is worth converting both your data and the quota to the same unit before choosing a plan.

Understanding Your Result

The headline is the converted size.

The conversion factor shows the exact factor both ways.

The in every unit line lists the size in bits, decimal and binary units.

The also line gives an everyday comparison: photos, songs or hours of video, or pages of text for small sizes.

When Should You Use This Calculator?

Use it when a new drive or card shows less space than its label.

Use it to compare cloud storage plans quoted in GB, TB, GiB or TiB.

Use it to check whether files will fit on a drive, card or upload limit.

Use it with memory chips and network figures given in bits.

Common Mistakes

Mixing bits and bytes. Mb is megabits; MB is megabytes, eight times larger.

Assuming GB always means 1,000 MB. Some software uses GB for 1,024 MiB.

Expecting the full label capacity. Formatting and system files take a little space.

Using binary factors for drive labels. Drive makers always use decimal units.

Rounding across units. Convert from the exact original figure, not a rounded one.