Yeast Conversion Calculator
Result
Converted
- Fresh yeast
- 21.00 g
- Active dry yeast
- 7.00 g
- Instant yeast
- 7.00 g
- Dry yeast, by volume
- 2.25 tsp
This yeast conversion calculator swaps between fresh yeast, active dry yeast and instant yeast, and gives you the amount in grams, teaspoons and packets at the same time. The ratio behind it is three to one: one gram of dry yeast does the work of three grams of fresh cake yeast. Active dry and instant yeast are interchangeable one for one, so the difference between those two is how you use them and not how much. Enter what you have, choose what it is and what you want, and read all three forms plus the teaspoon count.
Fresh, active dry and instant yeast by weight
| Fresh (g) | Active dry (g) | Instant (g) | Teaspoons (dry) | Packets |
|---|---|---|---|---|
| 9.33 | 3.11 | 3.11 | 1 | 0.44 |
| 18.9 | 6.3 | 6.3 | 2.03 | 0.9 |
| 21 | 7 | 7 | 2.25 | 1 |
| 42 | 14 | 14 | 4.5 | 2 |
| 84 | 28 | 28 | 9 | 4 |
Rows are anchored on the amounts a kitchen actually measures — a teaspoon, a third of a fresh cake, one packet, two, four. The active dry and instant columns are always identical, because those two are interchangeable one for one.
Formula
Fresh (g) = amount × fresh equivalent · Target (g) = Fresh (g) ÷ the target's fresh equivalent
- amount
- The weight of yeast you have
- fresh equivalent
- Grams of fresh yeast that one gram of this type replaces — 1 for fresh, 3 for either dry type
- fresh
- The amount expressed as fresh cake yeast, the common unit behind all three
- packet
- A 7 gram packet of dry yeast, which is 2¼ teaspoons
- teaspoon
- 3.11 grams of dry yeast, from 7 g ÷ 2¼
Reach for it when the shop only had one kind: a recipe asking for a block of fresh yeast when all you can buy is a sachet of instant, or a European recipe written in fresh yeast when your cupboard holds active dry. It is also the fastest way to find out what a packet of yeast is in grams and teaspoons, which is the question that actually comes up mid-recipe.
Worked examples
21 g of fresh yeast, converted to instant
- Fresh yeast is the base, so 21 g of fresh stays 21 g of fresh
- Divide by the fresh equivalent of dry yeast: 21 ÷ 3 = 7 g
- Active dry and instant are the same weight, so both read 7 g
- Teaspoons: 7 ÷ 3.111 = 2.25 — exactly the packet a supermarket sells
This is the anchor the whole page is built around: 21 g of fresh, 7 g of dry and 2¼ teaspoons are the same amount of yeast described three ways. If a conversion ever disagrees with that, one of the two is wrong.
A 2 oz block of fresh yeast, converted to active dry
- The block is 2 oz, which is 56.7 g of fresh yeast
- 56.7 ÷ 3 = 18.9 g of dry yeast
- In packets: 18.9 ÷ 7 = 2.7 packets
- In teaspoons: 18.9 ÷ 3.111 = 6.08
18.9 ÷ 7 = 2.7, and that is not a coincidence — it is the ratio between fresh and dry in the table many American sources publish. If you arrived from one of those, this page will look about 10% shy. Both numbers are in use; see the limitations below.
Limitations
Three to one is the ratio used here, from the Neapolitan rules and from the water content of the two yeasts, which works out at 3.07. Many American sources publish 2.7 instead, so a conversion read off those lands 10% below this one. The gap is real rather than an error: drying damages cells, so practical tables sit lower. In a dough that 10% is within tolerance — but a long cold ferment is where it shows. Fresh yeast is sold by weight, so no teaspoon figure is given.
Frequently asked questions
- How do I convert fresh yeast to dry yeast?
- Divide by three. 30 g of fresh cake yeast is 10 g of active dry or instant yeast, and a 7 g sachet replaces 21 g of fresh. Going the other way, multiply by three. Because there is no measuring spoon for fresh yeast, work in grams and use the teaspoon figure only for the dry side.
- Active dry vs instant yeast — are they the same?
- By weight, yes: they substitute one for one, and both manufacturers and baking references say so. The difference is in how you use them. Instant yeast can go straight into the flour; active dry is traditionally rehydrated in warm water first, though modern active dry is forgiving enough that most recipes no longer insist on it.
- How much is a packet of yeast in grams?
- 7 grams in the United States, which is 2¼ teaspoons and a quarter of an ounce. Packets in other countries are usually 7 g as well, but check — 5 g and 10 g sachets both exist, and a 10 g sachet is about 1⅓ times a US one. Seven grams of dry yeast is 21 g of fresh yeast.
- How many teaspoons of yeast are in a tablespoon?
- Three, and since a teaspoon of dry yeast is 3.11 g, a tablespoon is 9.3 g — about 1⅓ packets. Teaspoons are a poor way to measure yeast if you have a scale: how much a spoon holds changes with how it is scooped and how compacted the yeast is, which is why every figure on this page is derived from weight.
- Can I use sourdough starter instead of yeast?
- Not through this conversion — a starter is flour and water as well as yeast, so it has no single weight equivalence. A common starting point is 100 g of active starter per 500 g of flour in place of the commercial yeast, then adjust the flour and water in the recipe to allow for what the starter brings. That substitution is a change of method, not a unit conversion.