Top of climb
In aviation, the top of climb, also referred to as the TOC or T/C, is the computed transition from the climb phase of a flight to the cruise phase, the point at which the planned climb to cruise altitude is completed. The top of climb is usually calculated by an on-board flight management system, and is designed to provide the most economical climb to cruise altitude, or to meet some other objective (fastest climb, greatest range, etc.). The top of climb may be calculated manually with considerable effort.
Pilots of small airplanes need to do a flight plan to compute fuel usage and time of the trip, because they don't have a flight management system. Because climbing to cruise altitude burns fuel quicker, the takeoff to cruise altitude is calculated separately. The airplane's Pilot Operating Handbook has a table of fuel burned, time, and distance to reach a given altitude from sea level. To calculate the values for airport at 3000 feet, you subtract the values for sea level to 3000 from the sea level to cruise altitude.