What Is the Yeast Conversion Calculator?

Recipes aren't always written for the type of yeast you have on hand. DoughRise's free Yeast Conversion Calculator converts between fresh yeast, active dry yeast, instant (fast-action) yeast, and sourdough starter — giving you the exact substitute quantity so your recipe works as intended. No more guessing whether to double or halve.

Yeast Types Explained

Fresh yeast has the highest moisture content and shortest shelf life. Active dry yeast is partially dehydrated and needs rehydrating before use. Instant yeast is more finely ground and can be added directly to dry ingredients. Sourdough starter is a living culture — conversion depends on starter hydration and activity.

Open the Free Yeast Conversion Calculator →

Frequently Asked Questions

What is the conversion ratio for fresh to instant yeast?

Use roughly one-third the weight of instant yeast compared to fresh. So 15g of fresh yeast converts to approximately 5g of instant yeast.

Can I substitute sourdough starter for commercial yeast?

Yes, with adjustments. Active sourdough starter contains leavening organisms, but rise behaviour differs significantly from commercial yeast. Expect longer fermentation times and plan your schedule accordingly.

Do I need to proof active dry yeast before using it?

Yes — dissolve active dry yeast in warm water (35–40°C) for 5–10 minutes before adding to your dough. Instant yeast can be added directly to dry flour without proofing.