Question 1

How is raw image size calculated?

Accepted Answer

Raw size = width × height × color depth ÷ 8. A 1920×1080 image at 24-bit color (3 bytes per pixel) equals 1920 × 1080 × 3 = 6,220,800 bytes, or about 5.93 MB uncompressed.

Question 2

Are the compressed sizes exact?

Accepted Answer

No. Compressed sizes are statistical estimates based on typical compression ratios for each format. Real output depends on image content — photos compress better as JPEG, flat graphics compress better as PNG or WebP. Use it for planning, then verify the actual file.

Question 3

What color depth should I use?

Accepted Answer

Use 24-bit for standard color photos (8 bits each for red, green, blue), 32-bit when an alpha/transparency channel is present, 8-bit for grayscale, and 1-bit for black-and-white line art.