Yeast Conversion Calculator
Recipe calls for one type of yeast but you have another? Convert between fresh (cake), active dry and instant yeast so you can bake with whatever's in your cupboard, in the right amount.
How to use this calculator
- Enter the amount of yeast your recipe specifies (or that you have).
- Select the type you're converting from and to.
- Use the converted amount — and remember active dry needs proofing first.
Formula used
Dried yeasts are concentrated, so you need far less than fresh. Roughly: instant yeast is about a third the weight of fresh, and active dry about 40%. Instant is a touch more potent than active dry, hence the small difference.
Example calculation
7 g instant yeast (one typical sachet) ≈ ~8.4 g active dry ≈ 21 g fresh.
So a recipe wanting 25 g of fresh yeast needs only about 8.3 g of instant — dried yeast goes a long way.
Three yeasts, one job
Bread recipes come written for whichever yeast the author uses, but the three common types — fresh (cake) yeast, active dry, and instant (fast-action) — aren't interchangeable gram-for-gram. Fresh yeast is mostly water and the least concentrated, so you use the most of it; the dried forms are concentrated and need far less. The rough anchors are that instant is about a third of fresh by weight, and active dry about 40%.
Beyond quantity, they differ in handling. Active dry traditionally needs "proofing" — dissolving in warm liquid to wake it up — before joining the dough, while instant yeast is milled finer and can be mixed straight into the flour, which is why it's also called fast-action. Fresh yeast, favoured by some bakers for flavour, is crumbled in but is perishable and less widely sold. In a pinch instant and active dry are often swapped 1:1, but this converter gives the more accurate ratio when precision matters.
Why use this calculator?
- Bake with whatever yeast you have on hand.
- Precise conversions between fresh, active dry and instant.
- Reminds you which types need proofing first.
Frequently asked questions
How do I convert active dry to instant yeast?
Use about 25% less instant than active dry (instant is more potent), though many bakers swap them 1:1 in a pinch. More precisely, instant is roughly a third of fresh yeast's weight and active dry about 40%.
How much dry yeast equals fresh yeast?
Roughly: instant yeast is about a third the weight of fresh, and active dry about 40%. So 30 g of fresh yeast is about 10 g instant or 12 g active dry. Dried yeast is concentrated, so you need much less.
What's the difference between active dry and instant yeast?
Instant yeast is milled finer, is slightly more potent, and can be added straight to the flour. Active dry usually needs proofing (dissolving in warm liquid first) to activate. Both leaven bread well; instant is more convenient.