1
Pick your preset
Match the resolution and framerate you stream at. Custom bitrate works for non-standard captures or replay buffers.
Stream Recording Storage Calculator
Estimate the disk space your local recordings, VODs, and replay buffers will eat — by resolution, framerate, bitrate, codec, and stream length.
For OBS, Streamlabs, StreamUps Studio, and any other recorder. Free, instant, no signup.
Total recording size
11.1
GB (10.3 GiB)
Per hour
2.77
GB / hour
Recommended free space
13.3
GB (with 20% headroom)
Storage & encoder notes
- MKV is safer than MP4 for live recording — if your PC crashes mid-stream, MKV recordings are recoverable. Remux to MP4 after the stream for editing.
How To Use These Numbers
2
Reserve disk space
Use the 20% headroom number when planning your drive. OBS will stop recording mid-stream if your disk fills, and replay buffers eat extra GB.
3
Pick the right format
Use MKV for crash safety during long streams, then remux to MP4 after for editing. Multi-track audio requires MKV.
Recording File Size by Preset (GB / hour)
| Preset | x264 / NVENC H.264 | NVENC HEVC | AV1 | 8-hour stream |
|---|---|---|---|---|
| 720p30 — 3 Mbps | 1.4 GB | 0.9 GB | 0.7 GB | 11 GB |
| 720p60 — 4.5 Mbps | 2.1 GB | 1.3 GB | 1.1 GB | 16 GB |
| 1080p30 — 4.5 Mbps | 2.1 GB | 1.3 GB | 1.1 GB | 16 GB |
| 1080p60 — 6 Mbps | 2.8 GB | 1.7 GB | 1.4 GB | 22 GB |
| 1440p60 — 10 Mbps | 4.6 GB | 2.8 GB | 2.3 GB | 37 GB |
| 4K30 — 20 Mbps | 9.1 GB | 5.5 GB | 4.6 GB | 73 GB |
| 4K60 — 35 Mbps | 16 GB | 9.5 GB | 7.9 GB | 126 GB |
Estimates assume 160 kbps stereo audio. HEVC and AV1 sizes shown at the lower bitrate needed for visually-equivalent quality to H.264 — at the same bitrate, file sizes match H.264 exactly.
Skip the Local Recording Math
StreamUps Studio handles cloud-side recording for every multistream — your VOD is captured server-side without filling your local SSD. Stream as long as you want without worrying about disk space.
Frequently Asked Questions
How much storage do I need to record a stream?
A typical 1080p60 stream at 6 Mbps uses about 2.8 GB per hour, so a 4-hour stream needs roughly 11 GB. Multiply by your stream length and add 20% headroom for replay buffer, multi-track audio, and safety margin. The calculator above gives an exact number for your setup.
Does codec affect file size?
Only if you change the bitrate. At the same bitrate, x264, NVENC H.264, HEVC, and AV1 all produce the same file size. The advantage of HEVC and AV1 is that they look better at lower bitrates — so you can drop the bitrate and shrink the file. HEVC typically saves ~40%, AV1 ~50%, at visually-equivalent quality to H.264.
Should I record in MP4 or MKV?
Always record in MKV for crash safety. If OBS or your PC crashes mid-stream, MKV recordings stay readable; MP4 recordings can be lost entirely because MP4 only finalizes the index when recording stops cleanly. Remux MKV to MP4 (lossless, takes seconds) after the stream if you need MP4 for editing or upload.
How big is OBS replay buffer?
Replay buffer holds the last N seconds in RAM, then writes to disk only when you trigger a save. RAM use is roughly (bitrate Mbps × buffer seconds) ÷ 8 — so a 60-second buffer at 10 Mbps needs about 75 MB of RAM. Disk impact only happens on saved clips, where the file is the same size as a normal recording of that length.
Does multi-track audio make recordings bigger?
Yes — each extra audio track is added at full audio bitrate. Six tracks at 160 kbps adds about 432 MB to a one-hour recording compared to a single track. Multi-track recording requires MKV; MP4 only supports a single audio track.
Why is my recording bigger than the calculator predicts?
The most common cause is VBR (variable bitrate) encoding overshoot — VBR can spike well above the target bitrate during high-motion scenes. Another cause is multi-track audio counted as a single track. Check your encoder rate-control setting (CBR is more predictable for live streaming) and confirm how many audio tracks are recording.