Watch hours are a threshold, not a paycheck
YouTube doesn't pay per watch hour. The 4,000 hours are an entry requirement for the Partner Program's ad-revenue tier — once accepted, you earn from ad views on your videos, measured as RPM (revenue per 1,000 views). The same 4,000 hours can represent wildly different audiences: 48,000 five-minute views or 8,000 half-hour views, in niches that pay $2 or $30 per thousand.
A useful mental model: 4,000 hours at a typical 4-minute average view duration is roughly 60,000 views. At a general $2–10 RPM, that batch of views would have earned about $120–600 if monetized — which is why the first months after approval often feel underwhelming, and why niche matters more than volume.
What actually moves the number
Niche RPM (finance and business at $12–30 versus entertainment at $2–5), audience geography (US/UK/AU views pay several times more), video length (8+ minutes unlocks mid-rolls), and seasonality (Q4 ad budgets can double RPM versus January). Your real numbers live in YouTube Studio → Analytics → Revenue — and if you're still working toward the threshold, the Watch Time Calculator predicts your qualification date.