Number Conversion
Our Number Conversion category features 44 free tools designed to assist in converting various numerical systems and values between different formats. From base converters to percentage and fraction calculators, these resources offer a comprehensive suite of tools for users ranging from students performing homework assignments to professionals needing quick conversions for their work. Whether you are a scientist working on experiments or a programmer debugging code, this collection of tools can save time and ensure accuracy in your numerical calculations.
101 tools
Guide
About number conversion tools
Number conversion tools address the need to translate values between different numerical systems, whether for academic work, programming tasks, or engineering calculations. This category includes base converters that change numbers between binary, octal, decimal, and hexadecimal, as well as tools for converting between fractions, decimals, and percentages. Additional utilities handle specialized formats such as Roman numerals, Gray code, and scientific notation, while others translate between measurement units like parts per million and degrees. The collection serves anyone who needs to switch number formats quickly and accurately without manual calculation.
Before choosing a tool, it helps to understand the source and target formats involved. Binary, octal, decimal, and hexadecimal each use a different base, and conversion often requires grouping digits or applying positional notation. Fractions and decimals share a relationship through division, while percentages represent parts per hundred. When working with ppm, ppb, or ppt, remember that these are ratios scaled by powers of ten. Roman numeral conversion is limited to specific integer ranges, and Gray code differs from standard binary by changing only one bit at a time. Checking that the tool supports your particular base or unit prevents errors and rework.
Common mistakes include entering a value in the wrong base, assuming a decimal result is always simpler, or overlooking signed representations in binary tools. Some converters handle only positive integers, while others support signed magnitude, two's complement, or floating-point formats. Always verify that the output format matches your need—whether that is a pure number, a string label, or a scientific notation string. If you are converting text to binary or ASCII, be aware of character encoding standards that affect the result.
Find the right tool
Number Conversion tools by task
Base number systems
Base converters form the core of this category, handling the most common transitions between binary, octal, decimal, and hexadecimal. These tools are essential for computer science students, programmers, and anyone working with low-level data representation. The listed tools include binary-to-hex, hex-to-binary, decimal-to-octal, and a general number base converter that supports multiple output formats.
Decimal, fraction and percentage math
Tools in this group translate between decimal values, common fractions, and percentages—formats frequently used in finance, science, and daily calculations. Users can convert a decimal to a fraction, a fraction to a percent, or a percent back to a decimal. Separate calculators also handle the reverse directions, ensuring that whichever starting format you have, a matching tool exists.
Specialized and less common bases
Beyond the standard four bases, this theme covers converters for ternary, balanced ternary, quaternary, senary, septenary, duodecimal, and vigesimal systems. These tools are useful for niche academic work, historical studies, or specific digital logic designs. Each tool accepts a number in its named base and returns the decimal equivalent, often with a brief explanation of the conversion steps.
Radians, degrees and angle conversion
Angle conversion tools translate between degrees, radians, and degrees-minutes-seconds format. These are commonly used in trigonometry, physics, and engineering contexts. The category includes a degrees-to-radians converter, a radians-to-degrees converter, and bidirectional tools for converting between decimal degrees and DMS notation.
Binary representations and text encoding
These tools convert binary data into human-readable forms or between different digital encoding schemes. Binary-to-string and string-to-binary converters translate machine code into text, while hex-to-ASCII and ASCII-to-hex tools help developers read hex dumps. Additional converters handle Base64, Gray code, BCD, and signed magnitude formats for specialized computing needs.
Ratio, ppm and percentage scales
Tools that convert between parts per million, parts per billion, parts per trillion, and percentages are frequently used in chemistry, environmental science, and engineering to express very small concentrations. The category provides converters for ppm-to-percent, ppm-to-ppt, percent-to-ppm, ppb-to-ppm, and ppt-to-ppm, as well as a combined ppm converter that handles all these scales in one interface.
Roman numerals and date formats
Roman numeral converters handle translation between Arabic integers and Roman numeral strings, supporting numbers up to four million in either direction. A separate date-to-roman-numerals-converter changes calendar dates into Roman numeral format, which can be useful for historical projects or stylized numbering. Both tools accept standard input and produce the equivalent classical representation.
Questions
Number Conversion FAQ
- How do I convert a negative decimal to binary?
- Signed magnitude and two's complement are the two main methods used for representing negative numbers in binary. Signed magnitude keeps the magnitude positive and uses a separate sign bit, while two's complement inverts all bits and adds one. Check which format your coursework or code expects before using a converter.
- What is the difference between ppm, ppb, and ppt?
- These units express concentration at different scales: parts per million is one in a million, parts per billion is one in a billion, and parts per trillion is one in a trillion. Converting between them involves multiplying or dividing by powers of ten, and a dedicated ppm converter can handle all three plus percentages.
- Can I convert a Roman numeral that includes a bar over a letter?
- Roman numerals with a bar over a letter indicate multiplication by 1,000, so an V with a bar represents 5,000. Most online converters limit input to standard numerals without bars, typically covering values up to 3,999 or up to four million if extended rules are applied.
- Why does my binary-to-text conversion produce garbled characters?
- Binary-to-text conversion relies on a character encoding standard, most commonly ASCII or UTF-8. If the binary string was generated using a different encoding or includes extra padding, the decoded text may appear garbled. Using a converter that specifies the encoding helps ensure accurate results.
- Is it better to use a decimal-to-fraction calculator or do it by hand?
- A decimal-to-fraction calculator simplifies the process by automatically reducing the fraction to lowest terms, which is helpful for complex or repeating decimals. Manual conversion works well for simple terminating decimals, but the calculator saves time and reduces arithmetic errors for less obvious values.