Predict: Data Units & File Sizes
Make predictions about file sizes and unit conversions
How This Works
For each scenario, make a prediction BEFORE revealing the answer. This helps develop your intuition for data sizes and calculation skills.
Which is Larger?
Which of these represents MORE data?
- Option A: 5,000 KB
- Option B: 4 MB
Your prediction:
Image File Size
A digital photo has these properties:
- Resolution: 800 × 600 pixels
- Colour depth: 24 bits (true colour)
What is the approximate file size?
Your prediction:
Audio File Size
A music track has these properties:
- Duration: 4 minutes
- Sample rate: 44,100 Hz (CD quality)
- Bit depth: 16 bits
- Channels: Stereo (2 channels)
What is the approximate uncompressed file size?
Your prediction:
Text File Size
A novel has approximately:
- 80,000 words
- Average 5 characters per word (plus spaces)
- ASCII encoding (8 bits per character)
What is the approximate file size as plain text?
Your prediction:
Bits vs Bytes Trap
Your internet speed is advertised as 100 Mbps (megabits per second).
How long would it take to download a 100 MB file?
Your prediction:
Storage Planning
A photographer wants to store 1,000 photos. Each photo is:
- Resolution: 4000 × 3000 pixels
- Colour depth: 24 bits
What size memory card do they need (minimum)?
Your prediction:
Colour Depth Impact
Two identical images (1000 × 1000 pixels) are saved:
- Image A: 8-bit colour depth (256 colours)
- Image B: 24-bit colour depth (16.7 million colours)
How many times larger is Image B compared to Image A?
Your prediction:
Order These Units
Put these in order from smallest to largest:
- 1 nibble
- 1 GB
- 1024 bytes
- 1 MB
- 1 byte
Your prediction:
Sample Rate Impact
Two 1-minute audio recordings with the same bit depth (16-bit, mono):
- Recording A: 22,050 Hz (half CD quality)
- Recording B: 44,100 Hz (CD quality)
How does the file size compare?
Your prediction:
Real-World Estimation
A student types an essay with 2,000 words. Assuming:
- Average 5 characters per word
- Spaces between words
- ASCII encoding (1 byte per character)
Approximately how many essays could fit on a 1 MB drive?
Your prediction:
How Did You Do?
Developing intuition for file sizes takes practice. The more you work with these calculations, the better you'll become at estimating!
Key Takeaways:
- 8 bits = 1 byte - Always divide by 8 when converting bits to bytes
- ×1,000 between each unit (KB → MB → GB → TB)
- Image size depends on resolution AND colour depth
- Audio size depends on sample rate, bit depth, duration, AND channels
- bits vs bytes - Internet speeds use bits, file sizes use bytes!