It'd also be a good idea to use "cout << endl << endl" instead of using a new cout for each endl. Or do as I do, and if you have more than one endl right next to eachother, drop both of them and use "count << "\n\n" ". Same thing as "cout << endl << endl;" except you can get rid of that second <<.
Here's your code, a bit cleaned up.
using namespace std;
int main ()
double lspeed, rtime, htime; //Doubles are better than floats
cout << "\n\nRun Time Calculator";
cout << "\n\nEnter the distance in meters: ";
cin >> rmeters ;
cout << "\nWhat is the estimated speed? ";
cin >> lspeed;
rtime = rmeters / lspeed;
htime = ( rmeters / lspeed ) / 60;
cout << "\n\nYou have aproximately " << rtime <<" minutes ";
cout << " or " << htime << " hours of runtime.";
//Those last few cout << endl; s were useless.