Video bitrate & file size calculator
Size = bitrate × time. Pick which side you know.
1,596 kbps
video bitrate to land just under 20 MB for 1:30, after 128 kbps audio and 3% container overhead.
Rough fit with H.264: 480p–720p.
Typical bitrates (H.264, Mbps)
| Resolution | 60 fps | 24–30 fps |
|---|---|---|
| 2160p (4K) | 35–45 | 20–30 |
| 1440p | 16–24 | 10–15 |
| 1080p | 8–12 | 5–8 |
| 720p | 5–7.5 | 2.5–5 |
| 480p | 2.5–4 | 1–2 |
Ranges based on YouTube's recommended upload bitrates for SDR video. Sharing in chat apps usually needs far less.
See how bits per pixel decides quality
Where do the megabytes go?
A target size is a fixed pile of bits. Move the sliders and watch the video's share shrink.
2,459 kbps
for the picture, out of 2,667 kbps total (128 kbps audio, ~3% container overhead)
Bits per pixel per frame: 0.020
Starved. Expect smeared blocks, especially in fast motion. Drop the resolution or frame rate.
Sharpest safe choice here: 720p at 30 fps.
Questions people ask
How do you calculate video file size?
File size = (video bitrate + audio bitrate) × duration. With bitrates in kilobits per second and duration in seconds, divide by 8,000 to get megabytes. Example: (2,500 + 128) kbps × 60 s ÷ 8,000 ≈ 19.7 MB.
How do you calculate the bitrate for a target size?
Bitrate (kbps) = target MB × 8,000 ÷ seconds, then subtract the audio bitrate and a few percent for the container. For 20 MB and 90 seconds: 20 × 8,000 ÷ 90 ≈ 1,778 kbps total, about 1,630 kbps for video after 96 kbps audio and overhead.
What is a good bitrate for 1080p?
For H.264 at 30 fps, around 4–8 Mbps looks good for most footage; YouTube recommends 8 Mbps for 1080p30 uploads. Fast game footage needs more; talking heads need less. H.265 and AV1 can get similar quality at noticeably lower bitrates.
What is bits per pixel?
Video bitrate divided by (width × height × frame rate). It tells you how many bits each pixel gets per frame. Around 0.05–0.1 is comfortable for H.264; below about 0.02 the picture falls apart in motion.