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FFFF in Decimal

Hexadecimal FFFF equals 65535 in decimal.

Why this number matters: 65535 is the maximum unsigned 16-bit value (0xFFFF) and the highest TCP/UDP port number.

FFFF in all number bases

Decimal65535
Hexadecimal0xFFFF
Binary1111 1111 1111 1111
Octal177777

Try another value

Edit this value or switch its base. Your changes are calculated in your browser with exact integer arithmetic.

Input base:
Decimal65535
Hex0xFFFF
Binary0b1111111111111111
Octal0o177777

How ffff converts from hexadecimal to decimal

Multiply each digit by 16 raised to its position (starting at 0 from the right), then add the results:

F× 163 = 15 × 4096 = 61440
F× 162 = 15 × 256 = 3840
F× 161 = 15 × 16 = 240
F× 160 = 15 × 1 = 15

Sum: 65535

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Want to learn the method behind this tool? Read How to Convert Hexadecimal to Decimal - the full step-by-step guide.