Number Base Converter
Enter a decimal whole number and read it back in binary, octal, and hexadecimal — the three bases that computing relies on, all shown at once.
Three bases at once
One decimal input gives you base 2, base 8, and base 16 together, so you can copy whichever notation your tool or language expects.
Whole numbers from zero up
The converter takes non-negative integers; fractions and negative numbers use separate conventions (fixed-point, two's complement) not shown here.
What is a number base?
How many digits a system counts with
A number base, or radix, is how many distinct digits a system uses before it carries to the next place. Decimal (base 10) uses 0–9; binary (base 2) uses just 0 and 1; octal (base 8) uses 0–7; and hexadecimal (base 16) uses 0–9 then A–F. The value of a number never changes between bases — only the way it is written.
Enter a decimal number to see its binary, octal, and hexadecimal forms side by side, ready to paste into code or a calculator.
Repeatedly divide the decimal value by the target base and read the remainders from last to first — those remainders are the digits.
value = Σ digit × base^positionTake 2026. Dividing repeatedly by 16 gives remainders 10, 14, 7 — read upward that is 7, E (14), A (10), so 2026 is 7EA in hexadecimal. The same number is 11111101010 in binary and 3752 in octal. You can check hex by place value: 7×16² + 14×16¹ + 10×16⁰ = 1792 + 224 + 10 = 2026.
Each base is just a different costume for the same value, so 2026, 7EA, 3752, and 11111101010 all mean the identical quantity. Binary mirrors exactly how a computer stores data as on/off bits, but it gets long fast — eleven digits here. Hexadecimal is the popular shorthand because every hex digit maps to precisely four binary digits (a nibble), so 7EA unpacks cleanly to 0111 1110 1010; that is why colours, memory addresses, and byte values are usually written in hex. Octal groups bits in threes and shows up in Unix file permissions. When you read a value, watch for a base marker — a leading 0x means hexadecimal, 0b means binary, and 0o means octal in many languages — because the digits 10 mean two in binary, eight in octal, sixteen in hex, and ten in decimal.
Base conversion is exact, but it covers whole numbers only.
Integers only, and mind the base marker
This converter handles non-negative whole numbers. Fractions need a fixed-point or floating-point representation, and negative numbers are usually stored in two's complement, both of which follow separate rules not shown here. Hexadecimal output is uppercase (A–F); some tools expect lowercase, and the same string of digits means different values in different bases, so always label which base a number is in.