Enter the values you already know. This calculator can estimate a finished video file size, find the video bitrate that fits a target size, or show how long a storage card can record. It includes the audio stream, reports both decimal and binary units, and does all calculations in your browser. No video is uploaded.
Three calculations, one tool
Video bitrate and file size calculator
Choose what you need to find. Rates use bits per second; storage uses bytes.
Ready
Enter your values, then calculate.
Calculations run in this page and no video is uploaded. A copied share link visibly includes its numeric settings in the URL.
Where the calculator fits in DaVinci Resolve
Start on the Deliver page and choose Custom Export when you need direct control instead of a destination preset. After you select the format, codec and encoder, inspect the Quality controls. A rate field may appear as Restrict to with a value in Kb/s. Availability and wording can vary by codec, operating system and hardware encoder, so don't expect every render preset to expose the same field. If you need the surrounding controls, use the full Deliver-page walkthrough.
The file-size calculation
A byte contains eight bits, so the core conversion is simple: add the video and audio bitrates, multiply by duration in seconds, then divide by eight. The reverse calculation works from a target number of bytes back to bits per second. The calculator keeps full precision internally and rounds only the displayed result.
For example, 8 Mbps of video plus 384 kbps of audio for ten minutes is 628.8 MB before any optional allowance. A 500 MB target over ten minutes with 192 kbps audio leaves about 6.475 Mbps for video. A decimal 128 GB card at a total rate of 100 Mbps holds about 2 hours, 50 minutes and 40 seconds.
MB and GB are not the same as MiB and GiB
This page reports both systems because apps and storage vendors don't always label them consistently. Decimal units use powers of 1,000: 1 MB is 1,000,000 bytes and 1 GB is 1,000,000,000 bytes. Binary units use powers of 1,024: 1 MiB is 1,048,576 bytes and 1 GiB is 1,073,741,824 bytes. These prefixes follow the distinction described by the National Institute of Standards and Technology.
Current YouTube and Vimeo reference rates
The presets are shortcuts for planning, not secret best-quality settings. YouTube's current upload guidance recommends H.264 with variable bitrate and lists SDR reference rates of 8 Mbps for 1080p at standard frame rates, 12 Mbps for high frame rates, 35 to 45 Mbps for 4K at standard frame rates, and 53 to 68 Mbps for 4K at high frame rates. Its stereo audio recommendation is 384 kbps. Check the official YouTube upload encoding settings before a critical delivery because platform guidance can change.
Vimeo's current compression guidance recommends variable bitrate and gives broader ranges: 10 to 20 Mbps for 1080p and 30 to 60 Mbps for 4K, with AAC-LC audio at 320 kb/s. The presets use the low and high ends separately so the calculator never hides the range. See Vimeo's video and audio compression guidelines for the full table.
Why the rendered file can differ
The calculation is exact for a constant total data rate. A real export may differ because variable bitrate changes with scene complexity, the encoder may treat a requested limit as a target rather than a fixed ceiling, and the container adds metadata and indexing data. Extra audio tracks, embedded captions and other streams also consume space. Vimeo likewise identifies bitrate as the main driver while noting compression settings, metadata and other video properties as additional factors in its storage estimate explanation.
There is no trustworthy universal container-overhead percentage for every format and workflow. That's why the allowance starts at zero and remains under your control. For a hard upload cap, leave enough safety margin, render a short representative section, then check the actual output before committing to a long export.
Use the result without overfitting it
A target bitrate is a planning constraint, not a quality score. Resolution, frame rate, codec, encoder, motion, grain and source quality all affect how well a given rate holds up. If your destination is YouTube, pair the calculation with our DaVinci Resolve YouTube export settings. For broader format choices and export troubleshooting, start from the DaVinci Resolve export hub.
Video bitrate calculator FAQ
Does resolution determine video file size?
Not by itself. At a fixed total bitrate and duration, a 1080p and 4K file calculate to the same size. The 4K version usually needs more bitrate to preserve comparable detail, which is why platform recommendations rise with resolution and frame rate.
Why is my rendered file different from the estimate?
Variable bitrate, encoder behavior, container metadata, extra streams and rounding can move the final result. Treat the number as a planning estimate unless your workflow holds the total rate constant.
Where do I find bitrate in DaVinci Resolve?
Open the Deliver page and inspect the Quality controls for your chosen format and codec. A rate field may appear as Restrict to in Kb/s, but availability depends on the codec, encoder, operating system and hardware.
What is the difference between MB and MiB?
MB is decimal and contains 1,000,000 bytes. MiB is binary and contains 1,048,576 bytes. The calculator shows both so you can compare its result with whichever convention another app uses.
Can a bitrate calculation guarantee an exact upload size?
No. It can solve the mathematical target, but variable-rate encoding and container data can shift the finished file. Leave margin below a hard cap and verify the rendered output.
Does this calculator upload my video or inputs?
No. It doesn't ask for a video file, and the calculation runs locally in your browser. A share link stores only the visible calculator values in the page URL.
