The Quick Answer
10 GB is about 4 hours of HD video, a week of typical mixed use, or a month-plus of browsing, social and music. The spread is that wide because one activity dominates all others: video at high quality. Keep video on Wi-Fi and 10 GB is a comfortable month; stream HD on cellular daily and it's gone by Thursday.
| Profile | Daily cost | 10 GB lasts |
|---|---|---|
| Light — browsing, social, music; video on Wi-Fi only | ~0.3 GB | ~33 days |
| Typical — the above + ~30 min of HD video | ~1.5 GB | ~7 days |
| Heavy — 1–2 HD hours + calls on cellular | ~4 GB | ~2.5 days |