# How to decide on a rate of climb or descent if no specific vertical speed is required?

Obviously, obstacle clearance, charts, atc instructions etc. can require a specific rate of climb or descent, or at least pose limits that are easily calculated. When no such restrictions apply, there appears to be a large amount of freedom in selecting a vertical speed for reaching a certain instructed altitude. Are there standard rates in common use? What (preferably quantifiable) factors help pilots decide how quickly they want to get to their desired altitude?

In general terms, the higher you are the better your fuel efficiency, so you will want to climb quickly and then stay as high as you can until you need to start your descent in order to land. For jets, a common way to approximate your top of descent is by using the "3:1 rule" where you take your desired altitude loss in thousands of feet and multiply it by three. For instance if you need to lose 35,000 ft. you would start down 105NM ($\frac{35000ft \times 3NM}{1000ft}$) prior to your destination, staying at altitude until then in order to save fuel.