Video File Size & Bitrate Calculator

Comprehensive video calculator: estimate file sizes from bitrates, compute bitrates for upload file size targets, and calculate transfer times.

Calculate Video File Size from Bitrate & Duration

Video Duration

Video Bitrate

Audio Bitrate (Kbps)

Typical Resolution Presets:

Estimated Size (MB)

1,214.4 MB

Estimated Size (GB)

1.214 GB

Estimated Size (TB)

0.001 TB

⚠️ Important Distinction: Mbps vs. MB/s (Bits vs. Bytes)

Internet service providers (ISPs) quote download and upload bandwidth in Megabits per second (Mbps with a lowercase ‘b’). However, browsers, game launchers (Steam, Epic), and operating systems report file sizes and download speeds in Megabytes per second (MB/s with a capital ‘B’).

1 Byte = 8 Bits → Therefore: 1 MB/s = 8 Mbps

For example, a 100 Mbps internet connection yields a theoretical maximum download speed of 12.5 MB/s (100 ÷ 8). With realistic 5%–10% TCP/IP protocol overhead, expect real transfer rates around 11.5 MB/s.

How It Works

Combines video and audio bitrates, multiplies by duration, and converts bits to bytes.
Solves reverse equations to determine maximum allowed bitrate for upload limits (Discord, email).
Calculates download and upload durations across broadband speeds with protocol overhead factoring.
Clearly differentiates telecommunication bandwidth (Mbps) from disk file size (MB/s).

Formula & Technical Standard

File Size (MB) = [((Video Bitrate + Audio Bitrate) kbps * Duration sec) / 8] / 1000

Practical Example

10-minute 4K Video at 16,000 kbps

Input: 10 mins, 16,000 kbps video + 192 kbps audio

Output: Approx. 1.21 GB

Storage required before rendering.

Fit 60s Clip into 25MB Discord Limit

Input: 60 seconds, 25 MB limit, 128 kbps audio

Output: Target Video Bitrate: 3,205 kbps

Guarantees the rendered export does not exceed the platform ceiling.

Frequently Asked Questions

What is the difference between Mbps and MB/s?

Mbps (Megabits per second) measures data transmission speed and network bandwidth. MB/s (Megabytes per second) measures file storage size. Because 8 bits equal 1 byte, 100 Mbps internet provides a maximum theoretical download speed of 12.5 MB/s.

How do modern codecs affect bitrate?

Modern codecs like HEVC (H.265) and AV1 deliver approximately 30% to 50% better compression efficiency than legacy H.264 at equivalent visual quality.

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