Yeast Conversion Calculator
Swap between fresh, active dry and instant yeast without changing how the dough rises.
Fresh (cake) yeast is mostly water, so it takes about three times the weight of instant yeast to do the same work; active dry sits in between at about 1.
How the yeast conversion calculator works
Fresh (cake) yeast is mostly water, so it takes about three times the weight of instant yeast to do the same work; active dry sits in between at about 1.25 times instant. The ratios are 3 : 1.25 : 1 fresh : active dry : instant by weight. Active dry should be bloomed in warm liquid first; instant and fresh can go straight into the flour.
Formula: fresh : active dry : instant = 3 : 1.25 : 1 (by weight)
Worked examples
| Inputs | Use | Note |
|---|---|---|
| 20 g fresh → instant | 6.7 g | 6.7 g |
| 7 g instant → fresh | 21 g | 21 g |
| 10 g active dry → instant | 8 g | 8 g |
FAQFrequently asked questions
Can I swap yeast types one for one?
Not by weight. Fresh yeast is about a third as concentrated as instant and active dry sits between; the calculator does the 3 : 1.25 : 1 conversion for you.
Does instant yeast need activating?
No — instant (rapid-rise, bread-machine) yeast goes straight into the flour. Active dry should be dissolved in warm liquid (about 40 °C) for ten minutes first; fresh yeast is crumbled into the liquid or flour.
How much is a sachet?
A standard sachet of dry yeast is 7 g — enough for about 500 g of flour — which equals about 21 g of fresh yeast.
Will rising times change?
Slightly. Instant yeast works a little faster than active dry at the same equivalent dose, and fresh yeast gives a slower, gentler rise that many bakers prefer for flavour.
Where these figures come from
- US FDA — Safe Minimum Internal Temperatures — the internal temperatures the roasting calculator targets
- NIST SP 811 — Guide for the Use of the International System of Units — the exact weight and volume conversions used throughout
- Food Standards Australia New Zealand — food safety and labelling standards
Last checked: September 2026. Baking ratios follow standard baker's percentage practice; roasting guidance follows published safe internal temperatures.