Updated File & Media Tool

File Size Estimator

Estimate file sizes for text, images, audio and video content, convert between units and calculate upload/download time from your network speed. Quick, approximate calculations for planning storage and bandwidth.

Text Size Image Size Audio & Video Transfer Time

Estimate File Size and Transfer Time

Use the tabs below to estimate file sizes for text, images, audio and video, convert between bits/bytes/KB/MB/GB, and approximate upload/download times based on connection speed. All results are best-effort estimates and can vary from real-world files and codecs.

If this box is not empty, character count will be based on the text above.
Used only if no text is pasted.

For pasted text, the calculator measures bytes using UTF-8. For manual character counts, it uses simple per-character approximations (1 byte for UTF-8/ASCII, 2 bytes for UTF-16).

This tab estimates the uncompressed bitmap size: width × height × bits per pixel. Actual PNG, JPEG or WebP files are usually much smaller due to compression.

Common values: 128 kbps (standard), 192 kbps, 256 kbps, 320 kbps (high).

This tab assumes constant bitrate audio (CBR). Many modern formats use variable bitrate (VBR), so real file sizes can differ slightly.

Example: 5 Mbps for HD streaming, 8–12 Mbps for higher quality.

This tab estimates size from combined video + audio bitrates assuming constant bitrate over the whole duration. Actual codec efficiency and variable bitrate profiles can change real sizes significantly.

This converter uses binary-style storage units: 1 KB = 1024 bytes, 1 MB = 1024 KB, etc. For network speeds, units are typically decimal (1 Mbps = 1,000,000 bits per second).

Approximate loss to protocol overhead, congestion, etc. Default 10%.

This tab estimates time to transfer a file over a connection with a given nominal speed. Real-world times can vary due to overhead, latency, congestion, Wi-Fi quality and server limits.

File Size Estimator – Plan Storage and Bandwidth in Seconds

The File Size Estimator on MyTimeCalculator helps you quickly approximate file sizes for common media types and calculate how long uploads or downloads may take on a given network connection. It is designed for developers, content creators, IT teams and anyone planning storage, streaming or backup strategies.

All results are approximate. Real file sizes depend on encoding, compression, codecs, headers and metadata. That said, having a solid estimate is often enough to decide whether a network, disk or backup plan is adequate.

1. Estimating Text File Size

Text file size depends on character count and encoding:

  • ASCII: 1 byte per character (0–127 code points).
  • UTF-8: 1–4 bytes per character, depending on symbols and language.
  • UTF-16: Typically 2 bytes per code unit, sometimes 4 bytes for surrogate pairs.

The calculator can either measure an actual pasted text using UTF-8 bytes or estimate from a character count and a simple per-character rule of thumb.

2. Image Size from Resolution and Color Depth

Uncompressed image size is straightforward:

Size (bytes) = width × height × bits per pixel ÷ 8.

This gives you the raw bitmap size, which is useful for in-memory buffers or uncompressed formats. Files on disk (PNG, JPEG, WebP) are usually much smaller because they compress repeated patterns and smooth areas.

3. Audio Size from Bitrate and Duration

For constant bitrate (CBR) audio, file size depends on bitrate and duration:

Size (bytes) ≈ bitrate (kbps) × 1000 × duration (seconds) ÷ 8.

Bitrate is normally expressed in kilobits per second (kbps). Streaming services sometimes use variable bitrate (VBR) to adjust quality dynamically, which can cause real file sizes to deviate from simple CBR estimates.

4. Video Size from Combined Audio + Video Bitrates

For video with a separate audio track, the total bitrate is roughly:

total bitrate (bits/s) = video bitrate (Mbps) × 1,000,000 + audio bitrate (kbps) × 1,000.

The calculator then multiplies this by the duration and divides by 8 to get bytes. This gives a quick estimate when you know your target streaming or export bitrate.

5. Converting Between Bits, Bytes, KB, MB, GB and TB

Storage and memory are typically calculated with binary units:

  • 1 byte = 8 bits
  • 1 KB = 1024 bytes
  • 1 MB = 1024 KB
  • 1 GB = 1024 MB
  • 1 TB = 1024 GB

Network speeds, on the other hand, are usually in decimal units (1 Mbps = 1,000,000 bits/s). The unit converter tab uses binary-style storage units, while the transfer time tab uses decimal-style network units.

6. Estimating Upload and Download Time

To estimate transfer time, the calculator:

  • Converts the file size into bits.
  • Converts the connection speed into bits per second.
  • Applies an overhead percentage for protocol and real-world effects.
  • Computes: time (seconds) = file bits ÷ effective bits per second.

Use this as a planning tool rather than an exact measure. Congestion, Wi-Fi quality, server speed and other factors can significantly influence real transfer times.

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File Size Estimator FAQs

Frequently Asked Questions

Quick answers about how file sizes are estimated, what assumptions are used and why real-world files can differ from the calculator output.

Real files include codec overhead, headers, metadata, container formats and sometimes variable bitrate. The estimator uses simplified formulas based on resolution, bitrate and encoding assumptions, so it provides a realistic ballpark number, not an exact match byte-for-byte.

No. All calculations are intended to run in your browser using local JavaScript. The tool works with metadata like resolution, bitrate and pasted text, and any sample text or values remain in your browser session only. Still, you should avoid using untrusted devices for highly sensitive planning decisions.

Mbps stands for megabits per second (millions of bits per second) and is the most common unit for internet speed. MB/s stands for megabytes per second (millions of bytes per second). Since 1 byte = 8 bits, a 100 Mbps connection has a theoretical maximum of 12.5 MB/s before overhead and real-world losses.

Yes, as a guideline. If you know your target audio/video bitrates and typical viewer durations, you can estimate how much data each stream will consume and how much bandwidth you need. For precise planning, also consult your streaming platform’s analytics and recommendations, since they account for adaptive bitrate and real viewing patterns.

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