Bi-Directional Calculation
Solve for total file size given a target bitrate, or solve for the exact video bitrate needed to stay under 20 MB.
VIDEO UTILITIES · RUNS LOCALLY
Video bitrate calculator
Calculate video file sizes and target encoding bitrates for YouTube, TikTok, Discord, and Instagram. Avoid compression artifacts and file limit rejections.
FREE · NO ACCOUNT · ACCURATE ENCODING FORMULAS · ZERO UPLOAD
Codec:
Hours
Minutes
Seconds
Video bitrate (Mbps)12 Mbps
Audio bitrate (kbps)
Platform presets
Estimated file size
137.2 MB
137 MB total storage estimate
Video share of the file98%
Estimates assume a constant bitrate. Variable-bitrate exports and container overhead move the result by a few percent.
WHY THIS ONE
Hit upload caps without guessing render settings
Exporting at arbitrary bitrates causes oversized files that fail Discord or email limits, or low bitrates that turn footage into blocky pixel soup.
Codec Efficiency Standards
Includes efficiency baselines for H.264, HEVC (H.265), and AV1 so you pick the right encoder.
Quick Platform Presets
One-click presets for Discord limits (20 MB), email attachments, and YouTube recommended upload bitrates.
PAST THE PAGE
Generate and render cinematic video directly
PrismPoster Video Studio generates the footage from a prompt or a still, and the editor exports it.
- Generate the footage, then export from the editor at the size and length you planned.
- Plan the shots on a storyboard and render the board as one clip.
- In many countries a new account gets 200 free starter credits, no card. Unused starter credits expire 24 hours after they are granted.
This calculator is free with zero upload.
Explore Video StudioQUESTIONS
Video bitrate & encoding, answered
Is the bitrate calculator free?
Yes, with no account. It is arithmetic run on your device — nothing is sent anywhere.
How is the file size calculated?
Size in megabytes = (video bitrate + audio bitrate, in megabits per second) × duration in seconds ÷ 8. Container overhead is small, so real exports land within a few percent of the estimate.
H.264, HEVC or AV1 — which should I pick?
H.264 plays everywhere and is the safe upload. HEVC needs roughly 40% less bitrate for the same quality, AV1 about 50% — so a 20 MB cap holds a visibly better AV1 clip. Pick the newer codecs when the destination (YouTube, modern browsers, recent phones) supports them.
What bitrate fits under the Discord limit?
Free Discord uploads are capped at 20 MB. Switch to “Max bitrate from target size”, enter 20 MB and your clip length, and the calculator returns the highest video bitrate that still fits with the audio you chose.
What bitrate does YouTube recommend?
For SDR uploads YouTube suggests about 8 Mbps at 1080p (12 at 60 fps) and 35–45 Mbps at 2160p (53–68 at 60 fps), with 128–384 kbps AAC audio. Upload higher than that only if the source is genuinely cleaner — YouTube re-encodes everything.
Make the full version in the studio
Longer clips, higher resolution, sound, songs and a timeline editor — in one account.
200 free starter credits in many countries · No card · Unused starter credits expire after 24 hours
No subscription: credit packs from €3.99, paid once. The credits you buy never expire.
Start creating freeReady to render pristine video?Every frame at full fidelity.
Generate the scenes in the studio, then check the export against this calculator before you upload.