Hi there,
the answer to this question is about 744 million miles.
A recent study suggests that our DNA could stretch as far as the moon in our body.
We have about 10 trillion cells in our DNA and if we stretch all of them out it will be 744 million miles. Now this number could not be correct because scientists only made a hypothesis about this but it is the closest number we can get
So about 744 million miles should be the answer to this.
Hope this helped :)
Have a great day