Bread hydration calculator
A sourdough starter is made of flour and water too, so ignoring it gives the wrong hydration. Enter your flour, water and starter to see the real figure, or choose a target hydration and find out how much water to add.
Runs in your browser: nothing you enter is sent anywhere.
How to use it
- Choose whether to check the hydration of a dough you have planned or to find the water for a target.
- Enter the flour and water you add and the weight and hydration of the starter.
- Read the total flour, total water and hydration, which include the starter.
How it works
A starter of weight s and hydration h holds flour s ÷ (1 + h) and water s − s ÷ (1 + h). Total flour = flour + starter flour, total water = water + starter water, hydration = total water ÷ total flour × 100. For a target t, water to add = t × total flour − starter water.
Worked example
500 g flour, 350 g water and 100 g of 100% starter. The starter holds 50 g of flour and 50 g of water, so total flour is 550 g and total water is 400 g. Hydration = 400 ÷ 550 = 72.7%. To reach 75% instead: 0.75 × 550 = 412.5 g of water, minus the 50 g already in the starter, so add 362.5 g.
Tips
Frequently asked questions
What is hydration?
The weight of water divided by the weight of flour, times 100. 350 g of water with 500 g of flour is 70% hydration. Wetter doughs are more open and harder to shape.
How do I count the starter?
Split it into its flour and water. A starter at 100% hydration is half flour and half water by weight, so 100 g of it holds 50 g of flour and 50 g of water. Those amounts are added to the flour and water of the dough. A 60% hydration starter holds 100 g of flour for each 60 g of water.
What is my starter hydration?
It is the water divided by the flour you feed it with. Equal weights of flour and water give 100%; if you feed 100 g flour with 50 g water, it is 50%. If you are not sure, 100% is the usual default.
Does salt count?
No. Hydration compares water with flour only, so salt, seeds and other add-ins are not part of the calculation. See the baker percentage calculator for those.
Why is the hydration different from my recipe?
Many recipes quote hydration without the starter, or round it. Compare the total water and total flour lines to see exactly what is in your dough.