Yeast conversion calculator
21 g of fresh is 7 g of instant. Here is the rest.
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Next step
The yeast ratio only reads properly next to the hydration of the dough.
Where each number comes from Conversion constants are exact; densities and coverage rates come from cited sources; everything else is an assumption you can change. Methodology · Sources and updates
How to use it
- Type the amount of yeast you have or that the recipe calls for.
- Choose the type you have.
- Choose the type you want to convert to.
- The result shows all three equivalents at once.
How it is calculated
Converting between yeast types uses a widely accepted ratio:
From which the practical equivalents follow: a 7 g sachet of instant yeast equals about 21 g of fresh yeast, roughly half a 42 g block, or about 9 g of active dry yeast.
The difference between instant and active dry is the concentration of live cells: instant has more, so you need less. Fresh yeast is mostly water, hence the factor of 3.
Worked example
The recipe calls for 25 g of fresh yeast and you only have instant:
- In instant: 25 / 3 = 8.3 g
- In active dry: 10.4 g
- In teaspoons of instant: about 2.8
Good to know
- Brands vary. The 3 : 1.25 : 1 ratio is the usual reference, but every manufacturer has its own activity. Judge by how the dough rises.
- Active dry gets rehydrated. Traditionally dissolved in warm liquid before use; instant can go straight into the flour.
- Yeast is not a fixed schedule. Less yeast does not spoil bread: it just takes longer, and usually tastes better for it.
- Freshness. Yeast weakens over time. If the dough is not rising as expected, suspect the jar before the recipe.
Frequently asked questions
How much dry yeast equals 25 g of fresh?
About 8.3 g of instant yeast or 10.4 g of active dry, using the usual 3 : 1.25 : 1 ratio.
How much fresh yeast is one sachet of dry?
A standard 7 g sachet of instant yeast equals about 21 g of fresh yeast, half a 42 g block.
What is the difference between active dry and instant yeast?
Instant has a higher concentration of live cells and a finer granule, so you need less and it can go straight into the flour. Active dry is usually rehydrated in warm liquid first.
Can I use less yeast than the recipe says?
Yes, and it often improves the bread. Less yeast means slower fermentation and more developed flavour; it just needs more time.
Is the ratio exact?
It is a sensible reference, not a law. Brand and freshness change the outcome, so adjust according to how the dough responds.