A 64GB storage device can hold roughly 30 to 90 minutes of 4K video, depending on the codec and bitrate used. 4K video requires significantly more storage than lower resolutions because it captures four times the pixel data of 1080p. Most consumer 4K cameras and devices use H.264 or H.265 (HEVC) compression. H.264 typically requires 100–150 Mbps (megabits per second) for acceptable 4K quality, while the more efficient H.265 can deliver similar quality at 50–80 Mbps. At 100 Mbps, 64GB holds approximately 86 minutes of video. At 150 Mbps, you get roughly 57 minutes. With H.265 at 60 Mbps, you could store around 143 minutes. Professional or high-frame-rate 4K video (like 60fps cinema footage) uses even higher bitrates—potentially 200–400 Mbps—which reduces storage to just 30–60 minutes per 64GB. Smartphones and action cameras often compress more aggressively, sometimes fitting 90+ minutes in 64GB by using lower bitrates or optimized codecs. To estimate your specific scenario, check your device's bitrate in the camera settings or file properties. A rough formula: divide 64,000 MB by your bitrate in Mbps, then divide by 8 to convert bits to bytes.