Mtg Rate Calculator

The MTG Rate Calculator quantifies how many mythic-quality cards you can expect to pull when cracking booster runs, drafts, or sealed pools in Magic: The Gathering. Because mythic slots are a fixed probability per pack, understanding the adjusted rate after vault progress, promos, or special boosters helps you decide when to switch formats or open extra boxes.

Use the calculator to enter the number of packs you plan to open, the base mythic frequency for that set (often ~12.5% per booster in a regular set but higher for special releases), and any Vault or event bonuses that effectively raise the pull rate. Behind the scenes it multiplies the adjusted mythic rate by the run length, clamps it to 100% when necessary, and calculates the cumulative probability of seeing at least one mythic so you can forecast haul confidence.

Example: Opening 40 packs with a 12.5% base mythic rate and a 3% Vault boost yields roughly 6 expected mythics, an average of one mythic every 13 packs, and a 98% probability of seeing at least one mythic this run.