Denary Prefixes
The most common prefix system used is the Denary(Decimal) Prefix system. This is the system we use every day: Kilogram, Megabyte, Kilometer.
The denary prefix system works by each prefix being 1000 times larger than the previous prefix:
| Unit | Value | Power of 10 |
|---|---|---|
| 1 Kilobyte (KB) | 1000 Bytes | 103 |
| 1 Megabyte (MB) | 1000 Kilobytes (KB) | 103 |
| 1 Megabyte (MB) | 1,000,000 Bytes | 106 |
| 1 Gigabyte (GB) | 1000 Megabytes (MB) | 103 |
| 1 Gigabyte (GB) | 1,000,000,000 Bytes | 109 |
| 1 Terabyte (TB) | 1000 Gigabytes (GB) | 103 |
| 1 Terabyte (TB) | 1,000,000,000,000 Bytes | 1012 |
Sometimes you will see sizes shown in bits(b), instead of bytes(B), especially when talking about network speeds:
20 Mbps = 20 Megabits per second (notice the small b?)
What is the denary (decimal) prefix for 1000?
{"answers": {"A": "tera", "B": "giga", "C": "kilo", "D": "mega"}, "question_text": "What is the denary (decimal) prefix for 1000?", "correct_answer": "C"}
The [[decimal]] prefix mega represents 1000000
{"cloze_text": "The [[decimal]] prefix mega represents 1000000"}
Which unit is typically used to measure internet speed?
{"answers": {"A": "Megabits per second", "B": "Megabytes per second", "C": "Kilobits per second", "D": "Kilobytes per second"}, "question_text": "Which unit is typically used to measure internet speed?", "correct_answer": "A"}
Which unit is most commonly used to measure file size?
{"answers": {"A": "Terabytes", "B": "Megabytes", "C": "Gigabytes", "D": "Kilobytes"}, "question_text": "Which unit is most commonly used to measure file size?", "correct_answer": "B"}
When using decimal prefixes, calculations involve powers of [[10]]
{"cloze_text": "When using decimal prefixes, calculations involve powers of [[10]]"}
Conversion between Binary and Denary (Binary & Denary Prefixes)
Binary Prefixes â Kibi / Mebi / Gibi / Tebi
This works well where we humans count in denary (Powers of 10) but computers count in binary (Powers of 2) and therefore we need to use a binary prefix instead â Kibi, Mebi, Gibi, Tebi
Unit Value Power of 2 1 Kibibyte (KiB) 1024 Bytes 210 1 Mebibyte (MiB) 1024 Kibibytes (KiB) 220 1 Mebibyte (MiB) 1,048,576 Bytes 220 1 Gibibyte (GiB) 1024 Mebibytes (MiB) 230 1 Gibibyte (GiB) 1,073,741,824 Bytes 230 1 Tebibyte (TiB) 1024 Gibibytes (GiB) 240 1 Tebibyte (TiB) 1,099,511,627,776 Bytes 240
Binary & Denary comparison table
Here we can see the binary and denary prefixes side by side.
| Decimal Prefix | Decimal Value | Binary Prefix | Binary Value |
| kilo- (k) | 10^3 (1,000) | kibi- (Ki) | 2^10 (1,024) |
| mega- (M) | 10^6 (1,000,000) | mebi- (Mi) | 2^20 (1,048,576) |
| giga- (G) | 10^9 (1,000,000,000) | gibi- (Gi) | 2^30 (1,073,741,824) |
| tera- (T) | 10^12 | tebi- (Ti) | 2^40 |
The binary prefix [[mebi]] represents 1048576
{"cloze_text": "The binary prefix [[mebi]] represents 1048576"}
When using binary prefixes, calculations involve powers of [[2]]
{"cloze_text": "When using binary prefixes, calculations involve powers of [[2]]"}
Example Exam Question
Explain the difference between Megabyte (MB) vs Mebibyte (MiB)
Definition & Standards (1 mark)
- Megabyte (MB): Defined by the International System of Units (SI) and used in general science and storage marketing.
- Mebibyte (MiB): Defined by the International Electrotechnical Commission (IEC) for computing.
Size (1 mark)
- 1 Megabyte (MB) = 1,000,000 bytes (or 1000 x 1000 bytes)
- 1 Mebibyte (MiB) = 1,048,576 bytes (or 1024 x 1024 bytes)
Power Representation (1 mark)
- Megabyte: bytes
- Mebibyte: bytes
Number Base (1 mark)
- Megabyte: Base 10 (decimal system)
- Mebibyte: Base 2 (binary system)
Review: Fill in the Blanks
The denary prefix system is the most common prefix system and is used every day. Each prefix is times larger than the previous prefix, so 1 Megabyte is .
Denary prefixes use powers of , while computers count in binary using powers of . Binary prefixes are used to represent sizes in the system computers count in.
A Kibibyte (KiB) equals , which is represented by 2^. A Mebibyte (MiB) equals , or 1024 Kibibytes, and is represented by 2^.
A Megabyte (MB) equals and uses base 10, while a Mebibyte (MiB) equals and uses base 2. When discussing network speeds, sizes may be shown in instead of bytes (B); for example, 20 Mbps means 20 Megabits per .
Denary prefixes use powers of , while computers count in binary using powers of . Binary prefixes are used to represent sizes in the system computers count in.
A Kibibyte (KiB) equals , which is represented by 2^. A Mebibyte (MiB) equals , or 1024 Kibibytes, and is represented by 2^.
A Megabyte (MB) equals and uses base 10, while a Mebibyte (MiB) equals and uses base 2. When discussing network speeds, sizes may be shown in instead of bytes (B); for example, 20 Mbps means 20 Megabits per .
Click the keywords below to fill in the blanks:
1,048,576 Bytes
1000
1024 Bytes
Bits (B)
1,000,000 Bytes
10
20
1,048,576 Bytes
10
1000 Kilobytes
Second
2
â All blanks filled correctly! Great job!
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Introduction to Binary & Denary Prefixes
- Denary Prefixes
- Conversion between Binary and Denary (Binary & Denary Prefixes)
- Binary & Denary comparison table
- Example Exam Question