Arduino uno - calculating and outputting a time for each loop to execute?

TolpuddleSartre:
Whereabouts?

 unsigned long start_time=micros(); //record start time

unsigned long delta_t = micros() - start_time; //the difference


Right there.

See my reply 2

So how do I go about changing this to match your first reply which was to record values of micros at start and end of loop?