All tools
Converter

Yeast Conversion Calculator

Enter the yeast your recipe calls for, and see how much fresh, active dry or instant yeast to use instead.

Your recipe calls for

Fresh yeast is measured by weight, so teaspoons and packets are for dry yeast only.

g

Only used for the baker's percentages. About 4 cups of flour weigh 500 g.

Your conversion

21 g of fresh yeast works the same as 7.0 g (0.25 oz) of instant or active dry yeast.

Ratio
3 : 1fresh : dry
Your yeast
4.2%of the flour
Flour
500 g100%
  • Fresh (cake) yeast4.2%≈ 1/3 of a 2 oz cake · crumble into the flour or water21 g0.74 oz
  • Active dry yeast1.4%≈ 2 1/4 tsp · 1 packet · dissolve in some of the warm water7.0 g0.25 oz
  • Instant yeast1.4%≈ 2 1/4 tsp · 1 packet · mix straight into the flour7.0 g0.25 oz
Baker's percentages
IngredientWeightBaker's %
Flour500 g100%
Fresh (cake) yeast21 g4.2%
Active dry yeast7.0 g1.4%
Instant yeast7.0 g1.4%

Use one of the three amounts, not all of them. Teaspoons and packets are approximate: a teaspoon of dry yeast is taken as 3 g (King Arthur Baking) and a packet as 7 g (Red Star Yeast). Weigh small amounts if you can.

How it works

Dry yeast is fresh yeast with most of its water taken out, so it takes about a third as much to raise the same dough. Active dry and instant yeast are used one for one:

instant or active dry = fresh × 1/3

fresh = instant or active dry × 3

The calculator first turns your amount into grams (1 oz = 28.35 g, 1 tsp of dry yeast ≈ 3 g, 1 packet = 7 g, or the percentage times the flour), then applies the ratio. Baker's percentages are each yeast's weight divided by the flour's weight.

Worked example

  1. A European recipe calls for 21 g of fresh yeast and 500 g of flour: 21 ÷ 500 = 4.2%.
  2. 21 × 1/3 = 7 g of instant or active dry yeast, which is 1.4% of the flour.
  3. 7 g is one packet, about 2 1/4 teaspoons.

The one-third ratio is King Arthur Baking's (they write it as 0.33) and the AVPN's. Red Star Yeast's chart gives a third of a 2 oz fresh cake, about 19 g, for one packet, so expect sources to differ by a gram or two.

FAQ

How do I convert fresh yeast to instant or active dry yeast?

Multiply the fresh yeast by 0.33, or divide it by 3. That is the factor King Arthur Baking gives for both instant and active dry yeast, and the AVPN, the Neapolitan pizza association, uses the same one third. So 21 g of fresh yeast becomes 7 g of dry yeast, about one packet.

Can I use instant yeast instead of active dry yeast?

Yes, one for one by weight. Red Star Yeast says active dry may be substituted 1:1 for instant, and King Arthur Baking uses the same factor for both. Instant yeast works a little faster, so watch the dough rather than the clock. Some older guides say to use about 25% less instant yeast; that is a safe choice too if you want a slower rise.

How much fresh yeast equals one packet of dry yeast?

About 21 g (0.74 oz) by the one-third rule. Red Star Yeast, which still sells fresh cake yeast in 2 oz cakes, says a third of a cake, about 0.67 oz (19 g), matches one 1/4 oz packet, 2 1/4 teaspoons. The two figures are close enough for any bread or pizza dough.

Do I need to dissolve active dry yeast first?

It is the traditional way: stir it into some of the recipe’s warm water and wait a few minutes before mixing. Instant yeast goes straight into the flour. Fresh yeast can be crumbled into the flour or dissolved in the water; Red Star Yeast advises keeping it away from direct contact with salt or sugar.

Why does the calculator show baker’s percentages?

Many pizza and bread recipes give yeast as a percentage of the flour, for example 0.2% instant yeast. Pick "% flour" as the unit and enter your flour weight, and you get the same recipe with fresh or active dry yeast, in grams and as a percentage.

Sources