Lifestyle

Yeast Conversion Calculator

Convert between active dry, instant (rapid-rise) and fresh (cake) yeast while keeping the same rising power. Recipes call for whichever type the author had, but they are not interchangeable gram-for-gram: instant is stronger than active dry, and fresh is much weaker. Enter an amount and the type you have to get the right substitute, plus guidance on using each.

How to use this tool

  1. Enter the amount of yeast in grams (a standard sachet is 7 g).
  2. Choose the type your recipe or pantry gives you.
  3. Choose the type you want to substitute in.
  4. Read the equivalent weight, and the amount of all three types for reference.
  5. Follow the guidance note: instant mixes into flour directly, while active dry and fresh are usually proofed in warm liquid first.

The formula

Each yeast type has a different concentration of live cells, so equal rising power means different weights. The tool normalises to an active-dry equivalent, then scales to the target type.

instant ≈ 0.75 × active dry fresh ≈ 3 × active dry target = (amount ÷ source_factor) × target_factor
active dry
The baseline; granular yeast, usually proofed first
instant
Finer, more active; about 25% less needed
fresh
Cake/compressed yeast; about three times the weight

These are standard ratios. Yeast is forgiving — small differences mainly change rising time, not success — so round to a convenient amount.

Worked examples

Sachet of active dry to instant

Given
7 g active dry
Result
≈ 5.25 g instant

Instant is stronger, so you need about three-quarters as much for the same rise.

Dry to fresh

Given
7 g active dry
Result
≈ 21 g fresh

Fresh yeast is far less concentrated, so you need roughly three times the weight.

Fresh to instant

Given
30 g fresh
Result
≈ 7.5 g instant

Converting the other way, 30 g of fresh yeast replaces with about 7.5 g of instant.

Frequently asked questions

You can in a pinch, but the rise will differ. Instant yeast is about 25% more potent, so using the same weight of instant makes dough rise faster, and using the same weight of active dry rises slower. For best results, adjust the amount as this tool suggests.

No. Instant yeast is designed to be mixed straight into the dry ingredients. Active dry yeast is traditionally dissolved in warm liquid first to check it is alive, and fresh yeast is usually softened in liquid too, though modern active dry can often be added directly as well.

A standard sachet of active dry or instant yeast is 7 grams, about 2¼ teaspoons. Many recipes are written around this amount, which is why 7 g is the default here.

Not better, just different. Some bakers feel fresh yeast gives a subtle flavour and lively rise, but it spoils within a couple of weeks and is harder to find. Dried yeasts keep for months and perform reliably, which is why they dominate home baking.

Up to a point, then it backfires. Too much yeast can make dough rise so fast it develops little flavour and may collapse. Stick to the converted amount; a slower rise with less yeast usually tastes better.