1440p and 4K — About 2.5–10+ GB per Hour: Higher resolutions can quickly increase data consumption. 1440p may use several gigabytes hourly, while 4K can reach roughly 5–10 GB or more depending on bitrate, frame rate, codec, and video content.
Note: YouTube does not publish a fixed data-consumption figure for every playback resolution. Actual usage changes with codec, frame rate, video complexity, audio, buffering, and device settings.