Enter a value into any of the fields, and click on "Convert". Remember to "Clear All" before starting a new conversion.
Decimal
Binary
One's Complement
Two's Complement
Keep in mind, One's Complement has two representations of 0, +0 and -0. +0 is 00000000, and -0 is 11111111. Two's Complement only has the positive representation (00000000). Both One's Complement and Two's Complement are used to represent negative numbers, so if you input a positive number, its One's Complement and Two's Complement would be the same as its regular binary representation.
For floating point, use this website. If you're converting a binary number into its floating point representation, first convert the binary number into decimal, then use the aforementioned website to convert the decimal number into floating point. If you're converting from floating point to binary, then use the linked website, enter your floating point number into the "binary" input field, and then convert the resulting decimal into regular binary. Alternatively, use this website. Same concept as before.