Images and Sizes

Take an 800x600 px image:
800 × 600 = 480,000 pixes total

Assuming no compression:

• For RGB
  • 8 + 8 + 8 = 24 bits per pixel
  • (480,000 px × 24 bits/px) ÷ (8 bits / byte) = 15,360,000 bytes
  • 1,440,000 bytes = 1,406 kb = 1.37 Mb (divide by 1024 for each step)
• For 8-bit Indexed (256 colors)
  • 8 bits per pixel to reference the palette
    (480,000 px × 8 bits/px) ÷ (8 bits / byte) = 480,000 bytes
  • 256 colors in palette ÷ 256 bits per color = 65,536 bits = 8192 bytes
  • 480,000 + 8,192 = 488,192 bytes = 477 kb = 0.47 Mb

Either way, this isn't good.
The median total "page weight" for in 2021 was around 2 Mb

Compression

• Compression algorithms that are part of image formats
• Compression can be "lossy" or "lossless"