Yeast Conversion Calculator (Active Dry ↔ Instant ↔ Fresh)
Convert between active dry, instant, and fresh (cake) yeast for any recipe.
What this calculates
Yeast type isn't always what's on the store shelf. Active dry, instant, and fresh yeast are interchangeable with conversion factors based on dry-matter content. Instant has the most live cells per gram; fresh has the most water.
Formula & how it works
Instant = active dry × 0.75. Active dry = instant × 1.33. Fresh = active dry × 2.5 (or instant × 3.33). Always activate active dry in warm liquid; instant can go directly into flour.
Worked example
Recipe calls for 7 g active dry yeast. Instant equivalent = 5.25 g. Fresh equivalent = 17.5 g.
Frequently asked questions
Why convert?
Instant yeast is rounder, faster-acting, and doesn't need blooming. Many modern recipes assume instant; older ones often mean active dry.
How to tell yeast is alive?
Bloom test: 1 tsp yeast + ¼ cup warm water (110 °F) + 1 tsp sugar → should foam in 5-10 min. No foam = dead yeast.
Sourdough starter?
Different beast — wild yeast + bacteria. Doesn't convert from commercial yeast. See the sourdough-starter calculator.