Days to hours
One day is 24 hours, and this shows the working rather than just the answer. Nothing you type here leaves your browser — it is worked out on your own device, so there is nothing to send and nothing to log.
The factor
One day is 24 hours. That is the whole of the conversion: multiply by it, and nothing else happens.
What this page will not claim
It will not call this conversion exact. The factor is right to every figure shown, but at least one of these two units is not defined exactly in terms of the other, so there is a limit to how far the decimals mean anything.
The day is exactly 86,400 seconds. A real solar day wanders by a millisecond or two.
There is no shorter version
The factor is short enough to use as it stands, so nobody carries a rounded one and there is nothing to get wrong.
Going the other way
The reverse is not this sum backwards in your head. It is a different factor, 0.041666666667, and dividing by one is not the same as multiplying by a rounded version of the other.
Rounded, the way back is 0.0417, which is high by 0.08%. So the two roundings do not cancel: go out and back with both and you do not land where you started.
How many of those decimals mean anything
The box above will give you ten decimal places because it can. Whether they mean anything is decided by your measurement, not by the arithmetic.
If you measured to the nearest day, your figure is already uncertain by half of one — so the answer is uncertain by about 12 hours, and every digit past that is decoration. Quoting 29.62944 when you measured with a tape is claiming a precision the tape never had.
Where these two sit
Days and hours both measure time, which is why they can be converted at all. A conversion between families — a length into a weight — is not a conversion, it is a question with a missing quantity in it.
Other conversions from days
minutes · years (Julian) · weeks · seconds · milliseconds