Yeast Pitch Rate Calculator

Calculate how many billion yeast cells to pitch for your batch from the pitch rate, batch volume and wort gravity.

MetricUSImperial (UK)

Pitch rate (M cells/mL/°P)

About 0.75 for ales and 1.5 for lagers

Batch volume (L)

Volume of wort you pitch into

Wort gravity (SG)

11.9 °P

Yeast cells needed179billion cells

Do you have enough yeast?

Yeast type

Amount (mL)

At 1 billion cells per mL when fresh

Manufacture date

Printed on the package; fills in the days below

Days since manufacture (days)

Viable cells (88.7% viability)89billion cellsYeast starter neededYes(90 billion cells short)

Results are estimates provided "as is," for informational and planning purposes only, without warranties of any kind. Check them before you rely on them: you are responsible for decisions about your beer and equipment, including pressure and carbonation levels, the pressure ratings of your kegs and fittings, and any alcohol content you declare. Use of this calculator is subject to our Terms and Conditions.

Plan recipes and track every batch with these calculators built in. Foambyte is free to start.

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How the cell count is calculated

The pitch rate is expressed in millions of cells per milliliter of wort per degree Plato. Multiplying it by the volume and the gravity gives the cells to pitch:

\text{Cells}\ (\text{billions}) = \frac{r \times V \times P}{1000}

where $r$ is the pitch rate in million cells/mL/°P, $V$ the wort volume in milliliters and $P$ the gravity in degrees Plato.

For example, 20 L of wort at 1.048 (11.9 °P) pitched at 0.75 million cells/mL/°P needs about 179 billion cells. The same wort fermented as a lager at 1.5 needs about 357 billion.

Enter the gravity as specific gravity; the calculator converts it to degrees Plato.

Under Do you have enough yeast?, enter the yeast you have and its manufacture date. The calculator estimates its viable cells, as in the yeast viability calculator, and tells you whether you need a yeast starter.

Inside Foambyte, yeast is part of each recipe and batch, so pitch rates, cell counts and fermentation readings stay together.

Reference table

Billion yeast cells needed by wort gravity (rows), for ales at 0.75 and lagers at 1.5 million cells/mL/°P (columns)
Gravity	Ale, 20 L	Lager, 20 L	Ale, 5 US gal	Lager, 5 US gal
1.030 (7.6 °P)	113	227	107	215
1.040 (10.0 °P)	150	300	142	284
1.050 (12.4 °P)	186	372	176	352
1.060 (14.7 °P)	221	442	209	419
1.070 (17.1 °P)	256	512	242	484
1.080 (19.3 °P)	290	580	274	549
1.090 (21.6 °P)	324	647	306	612

Frequently asked questions

What pitch rate should I use?

A common rule of thumb is about 0.75 million cells per milliliter per degree Plato for ales and about 1.5 for lagers. Strong beers, cold fermentations and some yeast strains may call for more; check the recommendation of your yeast supplier.

Why does the wort gravity matter?

Denser wort has more sugar for the yeast to ferment and puts more stress on the cells, so the number of cells needed grows with the gravity.

How many packs or vials of yeast do I need?

Divide the cells needed by the number of healthy cells in each package. That number depends on the product and on how old it is, so check the manufacturer's cell count and date. A yeast starter can grow more cells from fewer packages.

What happens if I underpitch or overpitch?

Too few cells can lead to a slow or stuck fermentation and more off-flavors from stressed yeast. Far too many cells can reduce the yeast character some styles rely on. Pitching close to the target rate gives the most predictable fermentation.