Cooking and kitchen quantities

Sourdough feed ratio calculator

A 1:2:2 feed uses two parts flour and two parts water for each part existing starter.

Your numbers

Use the units shown. Results update as you change valid inputs.

YOUR RESULT

A 1:2:2 feed uses two parts flour and two parts water for each part existing starter.

THE NUMBERS, EXPLAINED

How to use this calculator.

A 1:2:2 feed uses two parts flour and two parts water for each part existing starter.

Start with your inputs

Enter starter mass (g), flour feed multiple, water feed multiple. Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.

InputExample value
Starter mass (g)20
Flour feed multiple2
Water feed multiple2

A worked example

With the example inputs above, flour feed (g) is 40. Change the inputs to explore your own scenario.

Putting the example numbers into the formula

Flour feed (g)
(20) × (2) = 40

Water feed (g)
(20) × (2) = 40

Total starter after feed (g)
(20) × (1+(2)+(2)) = 100

All results for the example inputs above
ResultExample answer
Flour feed (g)40
Water feed (g)40
Total starter after feed (g)100

How this is calculated

Flour feed (g)

a × b

Water feed (g)

a × c

Total starter after feed (g)

a × (1+b+c)

Symbols and units
a
Starter mass (g)
b
Flour feed multiple
c
Water feed multiple

Use the units shown. A list keeps the order in which you enter its values. The symbol ^ means “raised to the power of”.

Assumptions and limits

A 1:2:2 feed uses two parts flour and two parts water for each part existing starter.

Calculations use the values you enter. Blank or invalid inputs show an error instead of silently substituting zero. Results are displayed to useful precision; calculations retain the underlying numeric precision.

Questions about this tool

What does the result tell me?

Flour feed (g); Water feed (g); Total starter after feed (g). The result applies to the method and inputs described above. Check the units and assumptions before using it in a decision.

Why might another calculator differ?

Differences in units, rounding, timing or model definitions can produce different answers. Compare the input definitions and the method, rather than only the final number. For this tool: A 1:2:2 feed uses two parts flour and two parts water for each part existing starter.

Are my inputs stored or sent to AI?

Calculations on this page happen in your browser. The separate AI question finder sends its submitted conversation to OpenAI; these calculator fields are not sent. Favourites and recent tool names are stored locally. A shared link contains the inputs you choose to include.

Review status

Software example and browser checks are recorded in our quality report. No external expert review is claimed. Created with coding assistance; calculations run as ordinary browser code.

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