How is video file size calculated?

File size ≈ bitrate × duration. The tool first estimates a bitrate from resolution, frame rate, codec efficiency, and quality, then multiplies by seconds and converts bits to megabytes or gigabytes.

Which codec gives the smallest file?

AV1 is the most efficient, roughly 30–50% smaller than H.264 at equal quality, with H.265/HEVC in between. The trade-off is slower encoding and less universal playback support.

Why does my AI video file size matter?

When generating batches of clips you pay for storage and egress. Estimating size up front lets you choose a codec and resolution that keeps your storage bill predictable.

It is an estimate. Real bitrate depends on scene complexity and encoder settings — fast motion and detail push it higher than these averages. Use it for planning, not billing.

What is the Video Resolution & Bitrate Calculator?

Enter video resolution, frame rate, codec (H.264/H.265/AV1), and duration to calculate estimated bitrate, file size, and required bandwidth. Useful for estimating storage costs for AI video batches — runs in your browser. It runs free in your browser on Gera Tools, with nothing uploaded.

Video Resolution & Bitrate Calculator

Name: Video Resolution & Bitrate Calculator
Creator: Gera Tools
License: https://creativecommons.org/licenses/by/4.0/

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Video resolution and bitrate calculator

When you generate AI video at scale, file size drives your storage and bandwidth bill. This calculator estimates the bitrate, file size, and streaming bandwidth for any resolution, frame rate, codec, and duration — so you can plan storage for a batch of clips before you render them.

How it works

Bitrate is the data rate of the video stream, usually in megabits per second (Mbps). It scales with the number of pixels per second and the codec’s efficiency:

pixels_per_sec = width × height × fps
bitrate ≈ pixels_per_sec × bits_per_pixel × quality / codec_efficiency
file_size = bitrate × duration

Newer codecs need fewer bits per pixel for the same quality: H.265/HEVC is about 40% more efficient than H.264, and AV1 is more efficient still. The tool applies those factors and converts the result into a human-readable file size.

Reference: typical bitrates by resolution and codec

The table below gives illustrative bitrates for medium-quality output. Actual bitrates vary with scene complexity and encoder settings.

Resolution	H.264 (Mbps)	H.265/HEVC (Mbps)	AV1 (Mbps)
720p (1280×720) at 24fps	~5–8	~3–5	~2–4
1080p (1920×1080) at 24fps	~10–15	~6–9	~4–7
1080p (1920×1080) at 60fps	~20–25	~12–16	~8–12
4K (3840×2160) at 24fps	~35–50	~20–30	~12–20
4K (3840×2160) at 60fps	~60–80	~35–50	~20–35

These ranges are for reasonably complex content. Near-static AI-generated clips (smooth skies, gentle camera moves) will sit at the lower end. Fast action or high-detail scenes push toward the upper end.

File size planning example

For example, a batch of 50 AI-generated clips, each 8 seconds long at 1080p 24fps, encoded to H.264 at roughly 12 Mbps:

file_size per clip = 12 Mbps × 8 s = 96 Mb = 12 MB
total batch        = 50 × 12 MB = 600 MB

Re-encoding to H.265 at equivalent quality (~7 Mbps) cuts the total to about 350 MB — saving roughly 250 MB of storage per 50-clip batch. At scale (thousands of clips), this difference is meaningful for storage costs.

Tips

Re-encode AI outputs. Models often export bloated H.264 — re-encoding to H.265 or AV1 can halve storage with no visible quality loss for most viewers.
Match bitrate to motion. Static or slow-motion AI clips compress far smaller than fast action; treat the estimate as an average and expect variance.
Mind egress, not just storage. Serving video to viewers often costs more than storing it; lower bitrate cuts both costs simultaneously.
Cap frame rate for cinematic content. 24fps is the standard for cinematic AI video; stepping up to 60fps nearly doubles the bitrate and file size for content that will not obviously benefit from the extra smoothness.