Thrust-to-weight ratio

Thrust-to-weight ratio compares the maximum upward push an aircraft's motors can produce with the aircraft's own weight. A ratio of 1 to 1 can only just hover, so drones are usually built around 2 to 1 or higher to leave spare thrust for climbing, turning and correcting against wind. Higher ratios give quicker, more responsive control.

Example: A 5 kg drone whose motors together can lift 10 kg has a thrust-to-weight ratio of 2 to 1.