Yeast converter
Enter the yeast your recipe calls for, get the swap.
How much yeast is in a packet?
One standard packet of dry yeast is ¼ ounce, or 7 grams — about 2¼ teaspoons (Red Star, Fleischmann’s).
Can I use instant yeast instead of active dry?
Yes — King Arthur, Red Star and Fleischmann’s all say to swap them one for one. Lesaffre, which makes SAF yeast for professional bakers, suggests using a quarter less instant yeast; this calculator follows the one-for-one home-baking rule.
How do I convert fresh yeast to dry?
King Arthur’s baker chart multiplies fresh yeast by 0.4 to get active dry, so dry is about fresh ÷ 2.5. Brands round differently: Fleischmann’s says one 0.6-ounce cake equals one packet, and Red Star says one-third of a 2-ounce cake does.
Example
7 g of active dry yeast (one packet) = 7 g of instant yeast = about 17.5 g of fresh yeast — roughly one 0.6-ounce (17 g) cake.
Why can’t I measure fresh yeast in teaspoons?
Fresh (compressed) yeast is a moist block, so it is weighed or counted in cakes. Teaspoons and packets are for dry yeast.
How do I convert a recipe given in teaspoons into grams?
A packet is 7 grams and about 2.25 teaspoons, so one teaspoon of dry yeast is about 3.1 grams. A recipe that calls for 2 teaspoons of active dry yeast uses about 6.2 grams, and the same amount of instant yeast by the one-for-one rule, or 15.6 grams of fresh yeast. Weighing is more accurate than measuring spoons, because the density of dry yeast depends on how it is packed.
What if my recipe gives yeast as a percentage of the flour?
Bakers often write yeast as a percentage of the flour weight. If a recipe uses 1% instant yeast with 500 grams of flour, that is 5 grams of instant or active dry yeast, which is 12.5 grams of fresh yeast. The percentage is the same whatever the type, but the weight changes when you switch between dry and fresh yeast.
How the conversion works
The converter first turns your amount into grams (a packet is 7 grams, a teaspoon of dry yeast is 3.1 grams, and an ounce is 28.35 grams), then into a dry equivalent: fresh yeast is divided by 2.5, and active dry and instant yeast count one for one. The results are shown in grams and in the units of the form for each of the three types. The factor of 2.5 follows King Arthur's chart, in which fresh yeast is multiplied by 0.4 to get active dry yeast. Brands differ slightly and give factors from about 2.4 to 2.7, and the converter notes that. The cake size used is 0.6 ounces, about 17 grams.
Worked example: swapping fresh yeast for dry
A recipe calls for 21 grams of fresh yeast. Dividing by 2.5 gives 8.4 grams of active dry or instant yeast, which is 2.7 teaspoons or 1.20 of a 7 gram packet. In the other direction, one packet (7 grams) of dry yeast is 17.5 grams of fresh yeast. A 0.6 ounce cake of fresh yeast is 6.8 grams of dry yeast, which is close to a packet, in line with the way Fleischmann's equates one cake with one packet.
Active dry, instant and fresh
All three are the same species of yeast in different forms. Fresh yeast, also called compressed or cake yeast, is a moist block that must be refrigerated and used within a short time. Active dry yeast is dried in granules with a protective coating and is usually dissolved in warm water first. Instant yeast has finer particles that can be mixed straight into the flour. The home-baking brands in the FAQ above treat instant and active dry as interchangeable by weight, while professional guidance sometimes uses a smaller amount of instant. Rising times differ slightly between types and with temperature, so rely on the dough rising rather than the clock.
Common mistakes
Using teaspoons for fresh yeast is the first one; it must be weighed or counted in cakes. The second is applying the 2.5 factor in the wrong direction: you need more weight of fresh yeast than dry, not less. The third is treating baking powder or baking soda as yeast; they are chemical leaveners and do not convert at all. And the amounts here are rules of thumb: a very sweet, rich or cold dough may need more yeast, and the recipe's author is the better guide to the right quantity.
Sources: King Arthur Baking, yeast conversion chart (fresh × 0.4 = active dry); Red Star Yeast and Fleischmann's guidance on the 1/4 ounce packet and the equivalence of a packet to one cake of fresh yeast; Lesaffre (SAF) recommendations for professional use. Related: baker's percentage calculator, recipe scaler and cooking measurement converter.