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Number converters

Convert numbers between bases, Roman numerals, words, scientific notation, fractions, decimals, percentages, expanded form and ordinals.
Number Converters • Base • Roman • Words • Fractions • Scientific Notation

Number Converters

Convert numbers across the most useful mathematical and digital formats in one place. This all-in-one number converter supports binary, decimal, octal, hexadecimal, custom bases, Roman numerals, number names, ordinals, scientific notation, standard form, expanded form, fractions, decimals, percentages, and quick educational explanations.

Core formulas: Positional value uses \(N=\sum d_i b^i\). Scientific notation uses \(N=a\times10^n\), where \(1\le |a|<10\). Percent conversion uses \(p=\frac{x}{100}\).

Choose a Number Converter

Ready. Choose a converter and enter a value.

Result

11111111
255 in base 10 equals 11111111 in base 2.
Decimal255
Binary11111111
Octal377
HexFF
RomanCCLV
Scientific2.55 × 10²
ConversionValueMeaning

Batch Number Converter

Enter one decimal number per line. The batch tool returns binary, octal, hexadecimal, Roman numerals, scientific notation, and words when possible.

Conversion Steps

Steps will appear here after conversion.
Number converter workflow A visual diagram showing a number passing through different conversion formats. Input Number value Interpret Base, form, notation Convert Rules and formulas Output Chosen format One value can be represented as base notation, words, Roman numerals, percentages, fractions, or scientific notation. The value stays the same; only the representation changes.

What Are Number Converters?

Number converters are tools that transform a number from one representation into another. The value of the number stays the same, but the format changes. For example, the decimal number \(255\) can be written as \(11111111_2\) in binary, \(377_8\) in octal, \(FF_{16}\) in hexadecimal, \(CCLV\) in Roman numerals, “two hundred fifty-five” in words, and \(2.55\times10^2\) in scientific notation.

This page works as a complete number-conversion hub for students, developers, teachers, writers, data analysts, and anyone who works with numerical formats. It combines several common converters into one WordPress-ready tool: base converter, Roman numeral converter, number-to-words converter, ordinal converter, scientific notation converter, fraction-decimal-percent converter, and expanded-form converter.

The core idea is simple:

\[ Same\ value \rightarrow Different\ representation \]

The meaning does not change. Only the symbols, base, notation, or wording changes.

Major Number Conversion Types

ConverterExample inputExample outputBest for
Base converter\(255_{10}\)\(FF_{16}\)Computer science, programming, digital systems
Roman numeral converter2026MMXXVIDates, headings, clocks, classical numbering
Number to words12345Twelve thousand three hundred forty-fiveWriting, checks, education, accessibility
Ordinal converter2121st / twenty-firstRankings, lists, dates, positions
Scientific notation4,560,000\(4.56\times10^6\)Science, engineering, large and small numbers
Fraction-decimal-percent0.75\(\frac{3}{4}=75\%\)Math, finance, statistics, ratios
Expanded form5084250000 + 800 + 40 + 2Place value learning

Base Conversion Formula

A positional numeral system uses powers of its base. If \(b\) is the base, a number can be expanded as:

\[ N = d_n b^n+d_{n-1}b^{n-1}+\cdots+d_1b^1+d_0b^0 \]

For fractional values, the formula extends to negative powers:

\[ N=\sum_{i=-m}^{n}d_i b^i \]

In this expression, \(d_i\) is a digit and \(b\) is the base. The digit must always be smaller than the base. That is why binary allows only \(0\) and \(1\), octal allows \(0\) through \(7\), decimal allows \(0\) through \(9\), and hexadecimal allows \(0\) through \(9\) plus \(A\) through \(F\).

Binary, Decimal, Octal, and Hexadecimal

Binary, decimal, octal, and hexadecimal are the most common base systems in mathematics and computing. Decimal is the everyday system. Binary is the foundation of digital electronics. Octal appears in older computing contexts and Unix-style permissions. Hexadecimal is common in programming because it represents binary values compactly.

DecimalBinaryOctalHexadecimal
0000
1111
21022
31133
410044
510155
611066
711177
81000108
91001119
10101012A
11101113B
12110014C
13110115D
14111016E
15111117F
16100002010

Roman Numerals

Roman numerals use letters instead of place-value digits. The common symbols are:

SymbolValueExample
I1III = 3
V5IV = 4
X10IX = 9
L50XL = 40
C100XC = 90
D500CD = 400
M1000CM = 900

Roman numerals use subtractive notation for values like \(4\), \(9\), \(40\), \(90\), \(400\), and \(900\). For example, \(IV=4\) because \(I\) before \(V\) means \(5-1\). Similarly, \(IX=9\), \(XL=40\), and \(CM=900\).

Scientific Notation

Scientific notation writes very large or very small numbers using powers of \(10\). The standard form is:

\[ N = a\times10^n \]

where \(1\le |a|<10\) and \(n\) is an integer. For example:

\[ 4,560,000 = 4.56\times10^6 \]

Scientific notation is common in physics, chemistry, astronomy, biology, engineering, finance, and data science. It keeps numbers readable when ordinary notation becomes too long.

Fraction, Decimal, and Percent Conversion

Fractions, decimals, and percentages are three different ways to show the same ratio. The core relationships are:

\[ decimal=\frac{numerator}{denominator} \]

\[ percent=decimal\times100\% \]

For example:

\[ \frac{3}{4}=0.75=75\% \]

These conversions are heavily used in school math, statistics, finance, discounts, grades, probability, test scores, business dashboards, and everyday comparisons.

Expanded Form and Place Value

Expanded form breaks a number into the value of each digit. For example:

\[ 50,842 = 50,000 + 800 + 40 + 2 \]

Expanded form helps students understand that the digit \(5\) in \(50,842\) does not mean \(5\). It means \(5\times10,000=50,000\). The digit \(8\) means \(8\times100=800\). This is the foundation of place-value understanding.

Number to Words and Ordinals

Number-to-words conversion turns numeric symbols into readable language. For example, \(12345\) becomes “twelve thousand three hundred forty-five.” Ordinal conversion expresses position. For example, \(1\) becomes \(1st\), \(2\) becomes \(2nd\), \(3\) becomes \(3rd\), and \(4\) becomes \(4th\). In word form, these become “first,” “second,” “third,” and “fourth.”

Number words are useful for educational worksheets, legal documents, check writing, accessibility, invoices, certificates, and content publishing. Ordinals are useful for dates, rankings, class positions, race results, list items, and sequence descriptions.

How to Use This Number Converters Tool

  1. Choose the converter tab you need.
  2. Enter your number or expression in the input field.
  3. Select any required options such as base, precision, or output style.
  4. Click the conversion button.
  5. Review the main result, quick output cards, table values, and conversion steps.
  6. Use the batch converter when you need to process multiple decimal numbers.

Why This Page Does Not Include Exam Score Tables

Number converters are mathematical and computer-science utilities, not exam score calculators. Score guidelines, score tables, and next exam timetables do not apply directly to this page. The equivalent high-value information is correct conversion logic, formulas, examples, charts, notation rules, place-value explanations, Roman numeral rules, scientific notation rules, fraction-decimal-percent relationships, and practical use cases.

Number Converters FAQs

What is a number converter?

A number converter changes a number from one representation to another, such as decimal to binary, number to Roman numerals, decimal to percent, or standard notation to scientific notation.

What number systems are supported?

This tool supports binary, octal, decimal, hexadecimal, base 36, Roman numerals, number words, ordinals, fractions, decimals, percentages, scientific notation, and expanded form.

What is the formula for base conversion?

The formula is \(N=\sum d_i b^i\), where \(b\) is the base, \(d_i\) is each digit, and \(i\) is the place-value power.

What is scientific notation?

Scientific notation writes a number as \(a\times10^n\), where \(1\le |a|<10\) and \(n\) is an integer.

How do I convert a decimal to a percent?

Multiply the decimal by 100. For example, \(0.75\times100=75\%\).

How do I convert a fraction to a decimal?

Divide the numerator by the denominator. For example, \(\frac{3}{4}=3\div4=0.75\).

What is 255 in hexadecimal?

\(255_{10}=FF_{16}\).

What is 2026 in Roman numerals?

2026 is MMXXVI in Roman numerals.

Can this tool convert multiple numbers at once?

Yes. Use the batch converter and enter one decimal number per line.

Is this converter useful for programming?

Yes. It is useful for binary, octal, decimal, hexadecimal, scientific notation, and numerical formatting tasks used in programming and computer science.

Suggested internal links: numeral systems converter, binary to decimal converter, decimal to binary converter, Roman numeral converter, scientific notation calculator, fraction to decimal converter, percent calculator, and expanded form calculator.

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