WhiskMath

Yeast Conversion Calculator

Swap between fresh, active dry, and instant yeast by weight — exact amounts for any recipe.

g
Instant yeast
7.5 g
from 10 g active dry yeast
  • Conversion factor: ×0.75 (1 oz fresh = 0.4 oz active dry = 0.33 oz instant).
  • That's roughly 2.4 teaspoons of instant yeast (about 3.1 g per teaspoon).
  • Instant yeast can be mixed straight into the flour; active dry is best proofed in warm liquid first.
  • Fresh yeast is perishable — crumble it in and use it within a couple of weeks of purchase.
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How to use this calculator

  1. Enter the amount you have

    Type the weight of yeast your recipe calls for or that you have on hand, in grams.

  2. Choose the type you have

    Select fresh, active dry, or instant yeast as your starting type.

  3. Choose the type you want

    Select the yeast type you want to convert to.

  4. Read the converted amount

    The calculator applies the standard weight ratio and shows the equivalent amount, with a teaspoon estimate for the dried yeasts.

Recommended gear

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SAF Instant Yeast, 1 lb

Instant yeast stores well and skips proofing — a practical default once you have converted your recipe.

$8

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Escali Primo Digital Kitchen Scale

Yeast conversions work by weight, so a scale that reads to 1 gram makes them exact.

$25

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Yeast conversion ratios by weight

FromToMultiply by
Active dryInstant0.75
Active dryFresh2.5
InstantActive dry1.33
InstantFresh3
FreshActive dry0.4
FreshInstant0.33

All ratios come from 1 oz fresh yeast = 0.4 oz active dry = 0.33 oz instant.

Tips & best practices

  • Convert by weight, not by spoon — yeast types have different densities and weight is far more reliable.
  • Mix instant yeast straight into the flour; dissolve active dry yeast in warm liquid first.
  • Fresh yeast is perishable — crumble it in and use it within a couple of weeks of buying it.
  • Store dried yeast airtight in the freezer to keep it active for many months.
  • To test whether old yeast is still good, proof it in warm water with a pinch of sugar — it should foam within about 10 minutes.
  • Very hot liquid kills yeast — keep proofing water comfortably warm, not hot, to the touch.

Frequently asked questions

How do I convert active dry yeast to instant yeast?
Multiply the active dry amount by about 0.75 to get the instant yeast equivalent. Instant yeast is more concentrated, so you need a little less, and it can be mixed straight into the flour.
How do I convert fresh yeast to dry yeast?
To go from fresh yeast to active dry, multiply by about 0.4. To go from fresh yeast to instant, multiply by about 0.33. Fresh yeast contains moisture, so it weighs more than the dried equivalents.
What is the ratio between the three types of yeast?
By weight, roughly 1 ounce of fresh yeast equals 0.4 ounce of active dry yeast equals 0.33 ounce of instant yeast. Every conversion in this calculator comes from that single relationship.
Can I use instant and active dry yeast interchangeably?
Yes, with a small adjustment. Use about 25% less instant yeast than active dry, or about 33% more active dry than instant. The bigger difference is method — active dry is best dissolved in liquid first, while instant goes straight into the flour.
Do I need to proof instant yeast?
No. Instant yeast, sometimes labeled rapid-rise or bread-machine yeast, is designed to be mixed directly into the dry ingredients. Proofing in water is only necessary for active dry yeast or to test that old yeast is still alive.
How many grams of yeast are in a teaspoon?
Roughly 3.1 grams of instant yeast or about 2.8 grams of active dry yeast fit in a level teaspoon. Fresh yeast is sold by weight rather than spooned, so it is best measured on a scale.
Does converting yeast change the rise time?
Converting by weight keeps the leavening power roughly equal, so rise times stay similar. Instant yeast can act slightly faster, and a dough made with the converted amount should still be judged by how much it has risen, not by the clock alone.
Can I substitute yeast for sourdough starter?
Not with a simple weight ratio — starter and commercial yeast behave differently and a starter also adds flour and water to the dough. This calculator covers conversions among the three commercial yeasts only.

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Sources: King Arthur Baking yeast conversion guide; Red Star Yeast type and substitution charts.

Results are estimates for informational use. For food safety, always confirm meat doneness with a thermometer against current USDA guidance. WhiskMath does not provide medical or dietary advice.