Support: Binary, Hex and Decimal Converter

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Common questions

How do I convert binary to decimal?

Type the binary number in the Binary box. Each digit is a power of two, counted from the right starting at 1: 1010 is 8 + 2 = 10. The decimal box shows the answer as you type.

How do I convert hex to decimal?

Type the hex value in the Hexadecimal box, with or without 0x or #. Each hex digit is four bits, A to F stand for 10 to 15, so FF is 15 × 16 + 15 = 255.

How do I convert decimal to binary?

Type the number in the Decimal box. The Binary box shows it, grouped in fours, and the bits are drawn below with their place values.

What is two's complement?

The way computers store negative whole numbers: at a given width, -n is stored as 2 to the power of the width minus n. In 8 bits, -1 is 1111 1111. Choose a width to see it.

How big a number can it handle?

Any size. The converter works with whole numbers of any length, so 128-bit hashes and very long decimals convert exactly.

Can I convert fractions?

No, whole numbers only. Fractions in binary rarely end, which is why 0.1 cannot be stored exactly in a computer.

What bases can it use?

Any base from 2 to 36, using the digits 0 to 9 and then the letters a to z. Base 36 is sometimes used for short codes.

Is it free?

Yes, completely free, with no sign-up.