EB to Ebit converter

Understanding data storage units: exabytes and exabits

In digital data measurement, exabytes (EB) and exabits (Ebit) represent colossal units used for quantifying data at the exascale. One exabyte equals 1,000,000,000,000,000,000 bytes ($10^{18}$ bytes), while one exabit equals $10^{18}$ bits. Since 1 byte comprises 8 bits, converting between these units requires multiplication or division by 8. However, confusion arises due to two coexisting measurement systems:

• SI (decimal/base-10) system: Used by storage manufacturers and telecom companies. Units include exabyte (EB) and exabit (Ebit).
• IEC (binary/base-2) system: Used in software and computing. Units include exbibyte (EiB) and exbibit (Eibit), where 1 EiB = 1,152,921,504,606,846,976 bytes ($2^{60}$ bytes).

The discrepancy between systems stems from computing’s binary nature versus marketing’s decimal preferences. For example, a “1 EB” hard drive in SI terms might report as ~0.867 EiB in an operating system, causing real-world capacity mismatches.

The SI system (base-10) and IEC standard (base-2)

The International System of Units (SI) defines data units using powers of 10:

• 1 exabyte (EB) = $10^{18}$ bytes
• 1 exabit (Ebit) = $10^{18}$ bits

The International Electrotechnical Commission (IEC) standard uses powers of 2:

• 1 exbibyte (EiB) = $2^{60}$ bytes ≈ $1.1529 \times 10^{18}$ bytes
• 1 exbibit (Eibit) = $2^{60}$ bits ≈ $1.1529 \times 10^{18}$ bits

Historically, binary units were informally called “exabytes,” leading to ambiguity. The IEC formalized binary prefixes in 1998 to eliminate confusion. For instance, global internet traffic reports (often in Ebit) use SI, while RAM manufacturers use IEC.

Conversion formulas

Use these formulas for precise conversions. For SI units:

• EB to Ebit: $\text{Ebit} = \text{EB} \times 8$
• Ebit to EB: $\text{EB} = \text{Ebit} \div 8$

For IEC units:

• EiB to Eibit: $\text{Eibit} = \text{EiB} \times 8$
• Eibit to EiB: $\text{EiB} = \text{Eibit} \div 8$

For cross-system conversions (e.g., SI to IEC):

• EB to EiB: $\text{EiB} = \text{EB} \times \frac{10^{18}}{2^{60}}$
• Ebit to Eibit: $\text{Eibit} = \text{Ebit} \times \frac{10^{18}}{2^{60}}$

The ratio $\frac{10^{18}}{2^{60}}$ ≈ 0.8673617379884035 simplifies calculations.

Conversion reference table

Step-by-step examples

Example 1: SI system conversion

A data center stores 5 EB of data. To express this in Ebit:

$\text{Ebit} = 5 \times 8 = 40 \, \text{Ebit}$

Result: 5 EB = 40 Ebit.

Example 2: IEC system conversion

A server uses 3 EiB of memory. Convert to Eibit:

$\text{Eibit} = 3 \times 8 = 24 \, \text{Eibit}$

Result: 3 EiB = 24 Eibit.

Example 3: Cross-system conversion

An ISP advertises 100 Ebit/s bandwidth. Convert to Eibit/s (IEC):

$\text{Eibit/s} = 100 \times 0.8673617379884035 ≈ 86.736 \, \text{Eibit/s}$

Result: 100 Ebit/s ≈ 86.736 Eibit/s.

Example 4: Real-world discrepancy

A 1 EB cloud storage service (SI) reports capacity in EiB:

$\text{EiB} = 1 \times 0.8673617379884035 ≈ 0.867 \, \text{EiB}$

Explanation: Users see ~13.3% less capacity due to binary addressing.

Real-world applications and examples

• Internet backbone capacity: Subsea cables like MAREA (160 Tbit/s) are rated in SI units. 160 Tbit/s = 0.16 Ebit/s.
• Supercomputing: Frontier supercomputer’s 700 PB memory = 0.7 EB (SI) or ~0.607 EiB (IEC).
• Global data: Total internet traffic reached ~3.4 ZB (2024) – equivalent to 3,400 EB or 27,200 Ebit.
• Storage devices: A 20 TB HDD labeled in SI contains ~18.19 TiB (IEC), highlighting why OSes report lower usable space.

Why unit distinction matters

Misinterpreting EB vs. EiB causes financial and technical errors. In 2020, a cloud provider faced lawsuits after customers received 7.3% less storage than expected due to SI/IEC confusion. Scientific computing requires IEC for memory alignment, while network engineers use SI for bandwidth consistency.

Frequently asked questions

How to convert 2.5 EB to Eibit?

First, convert EB to Ebit (SI):

$\text{Ebit} = 2.5 \times 8 = 20 \, \text{Ebit}$

Then convert Ebit (SI) to Eibit (IEC):

$\text{Eibit} = 20 \times 0.8673617379884035 ≈ 17.347 \, \text{Eibit}$

What is the difference between EB and EiB?

EB (SI) is exactly 1,000,000,000,000,000,000 bytes ($10^{18}$). EiB (IEC) is 1,152,921,504,606,846,976 bytes ($2^{60}$). EiB is ~15.3% larger than EB.

Why does my 1 EB drive show only 0.867 EiB?

Storage vendors use SI units (1 EB = $10^{18}$ bytes), but operating systems use IEC units. Since $10^{18}$ bytes = $\frac{10^{18}}{2^{60}}$ EiB ≈ 0.867 EiB, the discrepancy is systemic.

How many EiB are in 50 EB?

$\text{EiB} = 50 \times 0.8673617379884035 ≈ 43.368 \, \text{EiB}$

This conversion is vital for data center planning, where physical storage must match binary addressing.