Free tool by DCAST
Duration and Size Calculator
Bitrate, codec, and file size. Plus encoding time: CPU vs GPU, H.264 vs HEVC vs AV1.
Bitrate, size and duration
Typical bitrate: 4–12 Mbps
Total bitrate = video + (audio × tracks).
Result
Approx. duration: 26.0 min at 5.13 Mbps total (H.264 / AVC)
Same visual quality, different codecs (approx. bitrate):
- H.264 / AVC: 5.00 Mbps
- HEVC / H.265: 2.75 Mbps
- VP9: 3.25 Mbps
- AV1: 2.25 Mbps
Encoding time (transcoding)
Estimated time to encode. Same settings: CPU is much slower than GPU; HEVC/AV1 slower than H.264.
NVENC H.264. Speed depends on preset and hardware.
Same codec and resolution: newer GPUs encode faster (more throughput per NVENC block).
Estimated encoding time
3.3 min – 7.5 min
For 60 min of 1080p → H.264 / AVC (NVENC H.264). Based on 24–30 fps source; 60 fps or complex scenes can take longer.