Steam Hours Calculator
Total hours across an entire Steam library, broken down by game.
Where the numbers come from
Steam records lifetime playtime for every game on an account and exposes it through the official Web API for public profiles. This tool sums those totals across the whole library. Steam does not publish day-by-day history, but MySteamStats can build a daily playtime heatmap for your account going forward if you sign in once with Steam.
For per-game lookups, try the game hours finder or read how to check hours on Steam for every native method.