Yeast Conversion Calculator
Convert between active dry, instant and fresh (cake) yeast in grams, ounces, teaspoons, packets or cubes. Choose the conversion rule your recipe uses, see all three yeasts at once and check the yeast against your flour.
How it works
Active-dry equivalent = amount ÷ from-factor · result = equivalent × to-factor · Factors by weight (active dry = 1): standard rule instant 0.75, fresh 2.5 · 1 : ½ : ⅓ rule instant ⅔, fresh 2 · packet rule instant 1, fresh 17 ÷ 7 ≈ 2.43 · 1 packet = 7 g ≈ 2¼ tsp (about 3.1 g per tsp) · Baker’s % = yeast g ÷ flour g × 100
Active dry, instant and fresh yeast are the same organism at different moisture levels and cell densities, so you convert them by weight. Instant is the most concentrated. Fresh (cake or compressed) yeast is about 70% water, so you need the most of it. Every conversion goes through an “active-dry equivalent”, so any pair converts cleanly. Published rules differ a little, and you can pick the one your recipe uses. The baker’s standard (the default) uses ¾ as much instant as active dry and 2½ times as much fresh. The 1 : ½ : ⅓ rule, common in European recipes, uses 2 parts active dry or 3 parts instant for every 6 of fresh. The yeast makers’ packet rule treats active dry and instant as equal and one ¼ oz packet as one 0.6 oz cake. The result is shown in grams, ounces, teaspoons and 7 g packets, or in cubes of fresh yeast of the size you buy. If you add the flour weight, you also get the yeast as a baker’s percentage. Rise times still vary: instant is fastest and needs no proofing.
Worked example
A recipe calls for 10 g of active dry yeast and you have instant. With the standard rule, 10 ÷ 1 = 10 g active-dry equivalent, and × 0.75 = 7.5 g of instant, about 2⅜ teaspoons or just over one 7 g packet. The same 10 g of active dry equals 25 g of fresh yeast (10 × 2.5), or 1½ cakes of 17 g. Going the other way, a European recipe with 42 g of fresh yeast (one cube) needs 42 ÷ 2 = 21 g of active dry, or 42 ÷ 3 = 14 g (2 packets) of instant, under the 1 : ½ : ⅓ rule.
Frequently asked questions
How much dry yeast replaces fresh yeast?
Divide the fresh weight by about 2.5 for active dry and by about 3.3 for instant (the baker’s standard), so 25 g of fresh becomes 10 g of active dry or 7.5 g of instant. The European 1 : ½ : ⅓ rule divides by 2 and 3, giving 12.5 g and 8.3 g. Either works; the dough just rises a little faster or slower.
How much is a packet of yeast?
A US packet (envelope) of active dry or instant yeast holds ¼ oz, which is 7 g or about 2¼ teaspoons. Yeast makers say one packet equals one 0.6 oz (17 g) cake of fresh yeast and raises up to about 4 cups (500 g) of flour.
Do I still need to proof instant yeast?
No. Instant (rapid-rise) yeast is milled finer and hydrates fast, so it goes straight into the dry ingredients. Active dry is traditionally dissolved in warm liquid (38–43 °C, 100–110 °F) first, though modern active dry also tolerates being mixed in dry.
Why is fresh yeast measured so differently?
Fresh (cake) yeast is roughly 70% water, so gram for gram it has far fewer live cells than the dried forms. That is why you need 2–2½ times the weight of active dry. When you swap fresh for dry in a big batch, add back the water the fresh yeast would have brought.
Will swapping yeast change my rise time?
Somewhat. Instant tends to rise fastest, active dry a touch slower, and fresh yeast is lively but perishable. Judge by the dough: it is ready when it has roughly doubled and springs back slowly when pressed.
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This calculator is for educational purposes. Double-check important results before acting on them.