Check the frame dimensions before choosing your export settings.
Video Bitrate Calculator
Find a video bitrate for your target file size, or estimate the size of an export. Include audio and leave a little room for the finished file.
Free to use · No account · No video upload needed
Plan the export before you render it
A file limit gives you a data budget. Pictures, soundtrack and file structure must all fit inside it. This video bitrate calculator shows the allowance for the pictures, giving you a starting value for your editor before you spend time rendering.
Choose Find bitrate for a size limit or Estimate size for an export bitrate. Both use the finished running time and combined audio bitrate. The result plans an export; it does not measure an existing file.
Check your source dimensions before choosing export settings · Check frame timing before planning your export
How to use the Video Bitrate Calculator
Start with the limit or the export setting
Enter your target size in MB, GB, MiB or GiB, checking the destination's unit. For storage planning, choose Estimate size and enter your average video bitrate. Compare the results before committing to an export.
Enter the full duration and audio budget
Include introductions, end cards and silent endings in the duration. Enter the combined bitrate of every audio track you will keep, or zero for silence. A stereo track's stated bitrate already includes both channels; you do not need to double it.
Leave room, then check the finished file
Reserve a percentage of the final size for the container and export variation. Two percent is an example, not a measured requirement. Enter the calculated video bitrate in an average-bitrate export setting, then inspect the finished clip and its actual size.
A worked example: two minutes under 100 MB
Suppose you have a two-minute product walkthrough, a 100 MB limit and one soundtrack at 128 kbps. A 2% reserve sets aside 2 MB. That leaves 98 MB for the video and audio streams combined.
Spread across 120 seconds, those streams have a total allowance of about 6.533 Mbps. Subtract 0.128 Mbps for audio and the picture gets approximately 6.405 Mbps, or 6,405 kbps. The soundtrack uses about 1.92 MB, leaving approximately 96.08 MB for the video stream.
The initial example uses these numbers. They demonstrate the calculation, not a quality recommendation: a quiet screen recording and fast-moving outdoor footage can need different settings.
What the result includes
Video bitrate is the average amount of data assigned to the pictures each second. Audio bitrate covers the soundtrack. Their sum is the combined stream bitrate. The complete file also contains a container structure: information that helps a player find, time and present those streams.
The reserve gives that extra data and export variation some room. It does not predict the exact container overhead. Extra audio tracks, embedded artwork, subtitles or other attachments may require a larger allowance or their own budget. For a strict upload limit, avoid treating the calculated ceiling as a guaranteed final size.
At the same duration, doubling the combined bitrate doubles the stream data. At the same size, doubling the duration halves the available combined bitrate. Trimming an unnecessary ending can free up picture data.
The arithmetic, with units kept visible
The video bitrate calculator converts the size to bits, subtracts the reserve and divides by duration. Subtracting the audio bitrate gives the amount available for pictures:
Video bits per second = target bytes × 8 × (1 − reserve fraction) ÷ seconds − audio bits per second.
For size estimates, add video and audio bitrate, multiply by duration and divide by eight. Divide again by one minus the reserve fraction to get the estimated total. Both modes use the same reserve definition, so their results are directly comparable.
MB and MiB are different units. Mbps means millions of bits per second, while MB/s means millions of bytes per second. At the same decimal scale, 8 Mbps equals 1 MB/s. A small letter can make a large difference to a calculation.
| File size unit | Bytes |
|---|---|
| 1 MB | 1,000,000 |
| 1 MiB | 1,048,576 |
| 1 GB | 1,000,000,000 |
| 1 GiB | 1,073,741,824 |
When the number is too small
Sometimes the soundtrack alone uses the available budget. The video bitrate calculator will explain that no positive video allowance remains. Increasing the target size, shortening the edit or reducing the audio bitrate can make the calculation possible. Entering a negative video bitrate would not solve the problem.
A positive result can still be too low for an acceptable picture. Look at motion, fine textures and small on-screen text in a short export. If those details break apart, try a shorter edit or a smaller frame size, or use a more efficient codec that your destination supports. Keep the source so you can revisit the export without repeatedly compressing an already compressed copy.
Useful before a deadline
Client reviews
Start with the attachment or upload limit and the exact length of the edit. Leave room for a slightly larger export, then check a short sample before rendering the whole job.
Courses and presentations
Compare several durations and bitrates. Long recordings leave less picture data per second under the same cap. Text-heavy slides may make readability more important than keeping every second of a recording.
Silent website backgrounds
Set audio to zero and estimate the size at your planned video bitrate. Try shorter loops as well as lower bitrates. Keep enough detail for the size at which the background will appear.
Video Bitrate Calculator FAQ
01Does this video bitrate calculator compress my video?
No. It calculates numbers from the values you enter. It does not open, upload, encode or change a video. Apply the result in an editor or encoder that supports an average video bitrate, then inspect the actual exported file. No account or payment is required to use the calculator.
02Is the result a recommended bitrate for 1080p or 4K?
It is a size-based budget. Resolution alone cannot tell you what will look good: motion, noise, codec and encoder settings matter too. A result that fits the limit still needs a visual check. The calculator does not certify a particular quality level.
03Should I enter the maximum bitrate or average bitrate?
Use the average bitrate when estimating a file size. A maximum setting is a ceiling for short sections, not necessarily the rate used throughout the video. Substituting that peak value can overestimate how much space the export will occupy.
04Can I use the result with a constant-quality export?
Constant-quality settings such as CRF or RF let the encoder decide how much data the footage needs. Their output sizes vary. If your editor offers an average-bitrate mode, that is the more direct place for this result; its quality setting is a different control.
05Why can the finished file be larger than the estimate?
The encoder may not hit the target average exactly, the audio may use a different rate, or the file may contain extra tracks and metadata. Check the duration and units, confirm the exported stream settings and leave more reserve for a strict limit.
06Can I calculate a silent video or multiple audio tracks?
Yes. Enter zero audio bitrate for a silent output. For several tracks, add their average bitrates together and enter the total. Only count tracks that will be in the finished file. Removing audio changes the budget, but it does not improve the existing picture.
07Is a higher bitrate always better?
More data can retain detail, but cannot restore what the source has already lost. Codec and settings also matter. Use the video bitrate calculator to plan space, then check quality during playback.
Try your own export numbers
Return to the video bitrate calculator, replace the example with your actual duration and size limit, and compare the available video budget. Keep the original, export a sample and check both the picture and the finished file size.