Video bitrate calculator: file size, bitrate and duration
This video bitrate calculator answers the three questions that come up whenever you record, export or upload video: how big will the file be, what bitrate fits a size limit, and how much footage fits on a memory card or drive. Pick what you want to work out, fill in the other values and the answer updates as you type, along with the size per minute and per hour.
Under the calculator are YouTube’s published upload bitrates for every resolution and frame rate, estimates for HEVC, VP9 and AV1, the hours that fit on cards from 16 GB to 2 TB, and the bandwidth needed to stream. You can also drop in a video to read its exact duration, size and audio bitrate; the file stays on your device.
How to use the Video Bitrate Calculator
- Choose what to calculate: File size, Bitrate or Duration.
- Enter the duration in hours, minutes and seconds and/or the file size in MB or GB.
- Enter the video bitrate in Mbps or kbps and the audio bitrate in kbps (0 for a silent video).
- Read the result, the size per minute and per hour, the hours per card and the streaming bandwidth.
- Unsure which bitrate to use? Choose a resolution, frame rate, dynamic range and codec under Recommended bitrate and press Use this bitrate.
Video Bitrate Calculator features
Three-way calculation
Size from bitrate and length, bitrate from size and length, or length from size and bitrate — with audio counted separately.
YouTube’s figures built in
SDR and HDR upload recommendations from 360p to 8K at standard and high frame rates.
Codec-aware estimates
HEVC, VP9 and AV1 values scaled from the H.264 figures by a clearly labelled rule of thumb.
Storage and bandwidth
Hours per card or drive, data used per hour of streaming and the upload needed for several viewers.
Reads real files
Drop a video to fill in its exact duration, size and audio bitrate, read locally by the Mediabunny library (MPL-2.0).
The formula behind the numbers
File size (bytes) = (video bitrate + audio bitrate) × duration in seconds ÷ 8. Bitrates are in bits per second and a byte has 8 bits. A 10-minute 1080p video at 8 Mbps with 128 kbps audio is (8,000,000 + 128,000) × 600 ÷ 8 = 609,600,000 bytes, about 610 MB. Turned around, bitrate = size × 8 ÷ duration, and duration = size × 8 ÷ bitrate.
Real files differ slightly: most encoders use a variable bitrate, so the average decides the size, and the container (MP4, MKV, WebM) adds an index and headers. Leave a few percent of margin when you aim for a limit. This page uses decimal units, as bitrates and storage makers do (1 MB = 1,000,000 bytes, 1 Mbps = 1,000,000 bits per second). Windows shows sizes in binary units but labels them MB and GB, so the same file looks about 5% smaller there, or 7% for gigabytes.
YouTube’s recommended upload bitrates (as of 2026)
From YouTube Help, “Recommended upload encoding settings”, checked in October 2026. The figures assume H.264 (High Profile) in MP4 with AAC-LC or Opus audio at 48 kHz; for audio YouTube suggests 128 kbps for mono, 384 kbps for stereo and 512 kbps for 5.1. They are upload figures for a service that re-encodes everything, so files you share directly can often use less — check the result by eye with the video compressor.
| Resolution | SDR 24–30 fps | SDR 48–60 fps | HDR 24–30 fps | HDR 48–60 fps |
|---|---|---|---|---|
| 8K (4320p) | 80–160 Mbps | 120–240 Mbps | 100–200 Mbps | 150–300 Mbps |
| 4K (2160p) | 35–45 Mbps | 53–68 Mbps | 44–56 Mbps | 66–85 Mbps |
| 1440p (2K) | 16 Mbps | 24 Mbps | 20 Mbps | 30 Mbps |
| 1080p | 8 Mbps | 12 Mbps | 10 Mbps | 15 Mbps |
| 720p | 5 Mbps | 7.5 Mbps | 6.5 Mbps | 9.5 Mbps |
| 480p | 2.5 Mbps | 4 Mbps | — | — |
| 360p | 1 Mbps | 1.5 Mbps | — | — |
Storage per hour at common bitrates
Gigabytes per hour = total Mbps × 0.45 (3,600 seconds ÷ 8 bits ÷ 1,000). Use it to size memory cards, cloud plans or a recording drive.
| Total bitrate | Per hour | Example |
|---|---|---|
| 1 Mbps | 0.45 GB | YouTube’s 360p upload figure |
| 5 Mbps | 2.25 GB | YouTube’s 720p figure |
| 8 Mbps | 3.6 GB | YouTube’s 1080p figure |
| 16 Mbps | 7.2 GB | YouTube’s 1440p figure |
| 45 Mbps | 20.25 GB | Top of YouTube’s 4K 24–30 fps range |
Video Bitrate Calculator FAQ
How do I calculate video file size from bitrate?
Add the video and audio bitrates, multiply by the duration in seconds and divide by 8. For example, 5 Mbps + 128 kbps for 2 minutes is 5,128,000 × 120 ÷ 8 = 76.9 MB. The calculator does this as you type.
What bitrate should I use for 1080p video?
YouTube recommends 8 Mbps for 1080p at 24–30 fps and 12 Mbps at 48–60 fps for H.264 uploads. HEVC or AV1 need less for similar quality, and clips you send directly can usually go lower.
How many hours of video fit on a 64 GB card?
At 8 Mbps video plus 128 kbps audio, about 17.5 hours. Pick Duration, enter the card size and your bitrate to see your own figure; cards show slightly less usable space than their label.
How do I find the bitrate a video file will need for a size limit?
Choose Bitrate, enter the size limit and the duration, and set the audio bitrate. The result is the video bitrate to use; aim a few percent lower for the container, or let the MP4 compressor hit the size for you.
Why is my real file a little different from the calculation?
Encoders vary the bitrate from scene to scene, containers add headers and an index, and Windows reports sizes in binary units. Expect a difference of a few percent.
What internet speed do I need to stream a video?
At least the video’s total bitrate, sustained, plus headroom for anything else using the connection. Check your connection with the internet speed test; to choose a bitrate for going live, use the live stream bitrate calculator.