Yeast Conversion Calculator
Convert between active dry, instant, and fresh yeast in grams, teaspoons, and packets.
What it does
Recipes call for yeast in whatever form their author had on hand: a packet, a spoonful, or a block of fresh cake. The three types are interchangeable once you know the ratios, and this tool converts between them in both directions.
The anchor is the packet. A standard envelope holds one quarter ounce, which is 7 grams of yeast, and that measures about 2.25 teaspoons. Most bread recipes written for home bakers build around that unit, so the tool uses it as its base and reports everything else against it.
Active dry and instant yeast swap one for one by weight in most recipes. The difference is handling, not quantity: instant yeast dissolves without proofing and can go straight into the dry ingredients, while active dry is often proofed in warm water first to confirm it is alive. Some bakers cut instant slightly and shorten the rise, but standard charts keep the ratio at one to one.
Fresh cake yeast is a different animal. It is perishable, sold in blocks, and about 2.7 times the dry weight for the same rising power. A 7 gram packet of dry yeast equals roughly 18.9 grams, or about two thirds of an ounce, of fresh yeast. That is why a single packet is often written as two thirds of an ounce on conversion charts.
Because fresh yeast is weighed, the tool asks for grams or ounces whenever you pick it, and it refuses spoons or packets for that type. Everything else converts freely: packets to grams, grams to teaspoons, ounces to packets, and back again.
How to use
- Enter the amount the recipe or the packet states.
- Pick the unit it is measured in: teaspoons, grams, ounces, or packets.
- Pick the yeast type you have.
- Read the active dry and instant lines for dry yeast equivalents.
- Read the fresh line for cake yeast, which appears in grams and ounces.
- Round to your scale's precision and note the type you actually bought.
Formula
- 7 g
- Dry yeast in one packet, which is also 2.25 teaspoons.
- 2.25
- Teaspoons per packet when level scooped.
- 2.7
- Fresh cake yeast weight per unit of dry yeast.
- 28.3495
- Grams per ounce for ounce based entries.
The 2.7 ratio comes from the standard packet equivalences: 7 g dry and 2/3 oz (about 18.9 g) fresh rise the same dough. Active dry and instant both report the same dry figure, because charts treat them as one to one.
Worked example
Example: 2.25 tsp of active dry yeast
The default: 2.25 teaspoons of active dry yeast, which is one packet.
- Teaspoons to grams: 2.25 x 7 / 2.25 = 7 g.
- Packets: 7 / 7 = 1 packet.
- Active dry equivalent: 7 g (2.25 tsp, 1 packet).
- Instant equivalent: the same, since the two swap one for one.
- Fresh cake: 7 x 2.7 = 18.9 g, about 0.67 oz.
Reference table
| You have | Dry yeast | Also equals |
|---|---|---|
| 1 packet (1/4 oz) | 7 g | 2.25 tsp |
| 1 tsp | 3.1 g | 0.44 packet |
| 1 tbsp | 9.3 g | 1.33 packets |
| 1 oz fresh cake | 10.5 g dry | 3.37 tsp |
Limits
- Uses the standard equivalence; some bakers trim instant yeast slightly and let doughs rise a little faster.
- Fresh yeast is converted by weight only, since no standard spoon measure exists for it.
- Storage and age change how lively a given amount of yeast still is.
- Does not adjust for dough temperature, sugar levels, or proofing method.
Common mistakes
- Treating a packet as one tablespoon; it is 2.25 teaspoons.
- Using the fresh ratio in the wrong direction, which triples instead of dividing by 2.7.
- Proofing instant yeast when the recipe expects it straight in the dry mix, wasting time rather than dough.
- Measuring teaspoons loosely; a heaped spoon can carry almost twice the yeast of a level one.
- Assuming a biga or sponge changes the conversion; it changes the schedule, not the weight.
Try it yourself
Quick checks. Answers sit tucked under each question.
A recipe wants 2 packets of instant yeast. How much active dry yeast is that?
The same: 14 g, or 4.5 teaspoons.
You have 21 g of active dry yeast but only fresh cake yeast in the fridge. How much fresh yeast?
56.7 g, about 2 ounces.
How many grams is 1 teaspoon of active dry yeast?
3.1 g, which is just under half a packet.
Questions
How many grams is a packet of yeast?
7 g, which is also one quarter ounce and about 2.25 teaspoons.
Are active dry and instant yeast interchangeable?
Yes, one for one by weight. Instant dissolves without proofing; active dry is often proofed first.
How much fresh yeast equals a packet?
About 18.9 g, or two thirds of an ounce, of fresh cake yeast.
Can I use fresh yeast in any bread recipe?
Yes, crumbled into the liquid. Expect a slightly faster start, since fresh yeast wakes up quickly.
Why does the tool reject spoons for fresh yeast?
Recipes weigh fresh yeast because it is dense and sticky. Grams and ounces keep the conversion honest.
Does instant yeast need less than active dry?
Standard charts say no. Some bakers shave off a quarter since instant acts faster, but the one to one ratio bakes reliably.
Sources
- Red Star Yeast: yeast conversion chart and packet weights
- University of Illinois Extension: yeast varieties and how to use them