Yeast Conversion Calculator
Enter the amount your recipe asks for and choose which kind of yeast you actually have.
A standard UK sachet of instant yeast is 7g.
Answer
21 g of fresh yeast
Equivalent quantities
Those three amounts do the same job. As a rule of thumb, dried is half fresh, and instant is a third of fresh.
- Crumble into the liquid. Keeps about two weeks in the fridge.
- These ratios are the standard UK baking figures, but brands do differ. Check the packet if it gives its own conversion.
- The three types do not behave identically. Fresh yeast gives the gentlest, best-flavoured rise; instant is the most reliable; active dried needs waking up first.
- Yeast quantity changes how fast dough rises, not how good it is. A slow rise with less yeast usually tastes better.
Source: Standard UK and US kitchen reference weights and manufacturer guidance · Reviewed 2026-09-10 · Guidance version 1.0.0
Reference and detail
The three kinds, and what they want from you
Fresh yeast is the beige block from a bakery or chilled counter: crumble it into the liquid. Active dried yeast is coarse granules and needs waking in warm liquid for ten to fifteen minutes before it meets the flour. Instant or easy-bake yeast is a fine powder that goes straight in with the dry ingredients, and it is what almost every UK supermarket sachet contains.
Less yeast, better bread
The amount of yeast controls how fast dough rises, not how good it is. A smaller quantity and a longer, cooler rise (overnight in the fridge, say) gives noticeably more flavour than a fast rise with a full sachet.
Is it still alive?
Dried yeast loses power once opened, so keep it sealed in the fridge and note the date. To test it, stir a teaspoon into warm water with a pinch of sugar: it should be foaming within ten minutes. If nothing happens, the yeast is dead and the dough will not rise no matter how long you wait.
Questions and answers
Questions about converting between types of yeast
Can I use instant yeast in a recipe that calls for fresh yeast?
Yes, but not in the same quantity, fresh, active dried and instant yeast have different strengths for the same rise. Enter the amount and type your recipe specifies in the calculator above to find how much of the yeast you actually have to use.
How many 7g sachets of yeast do I need for a recipe?
Enter the recipe's yeast amount above and it will tell you how many standard 7 g UK sachets that comes to, since sachets are the usual way instant yeast is sold here.
Does using more yeast make bread rise better?
No, the amount of yeast changes how fast dough rises, not the quality of the result. A smaller amount with a longer, cooler rise, such as overnight in the fridge, generally gives more flavour than a large amount and a fast rise.
How do I know if my dried yeast is still active?
Stir a teaspoon of it into warm water with a pinch of sugar and leave it for ten minutes; it should foam. If nothing happens, the yeast is dead and won't raise the dough, however long you wait.