Enter flour, water and starter weights plus your starter's hydration to get the true total hydration of your dough and the final dough weight.
Your results will appear here.
Enter your values and press Calculate.
Hydration is the weight of water divided by the weight of flour, times 100: a simple ratio scaled so flour always equals 100. The tricky part with sourdough is that your starter already contains both flour and water, so this calculator splits the starter into its two parts first. A 100 g starter at 100 percent hydration is 50 g flour and 50 g water; at any other starter hydration the split follows the formula starter flour = starter weight × 100 / (100 + starter hydration percent), with the rest counted as water. Those starter parts are added to your recipe flour and water to get the true totals, and true hydration is total water / total flour × 100. The calculator also reports the total flour and water in grams and the final dough weight, which is simply flour plus water plus starter. Weigh everything on a digital scale in grams for results you can repeat; volume cups are not accurate enough for hydration math.
Hydration describes how wet your dough is relative to its flour, expressed as a baker's percentage where flour is always 100 percent. A 70 percent hydration dough uses 70 g of water for every 100 g of flour, counting the water already inside the starter. That single number predicts a lot: how sticky the dough feels, how fast it ferments, how open the crumb becomes, and how hard it is to shape. The hydration chart of ranges in the next sections helps you read any recipe at a glance, and the calculator gives you the true number for your own formula instead of a guess.
Weigh your flour, water and ripe starter in grams and enter the three weights. Enter your starter's hydration percent: 100 for the common equal-parts starter, around 50 to 65 for a stiff starter, or above 100 for a liquid one. The calculator instantly shows the true total hydration, the flour and water hiding inside your starter, and the total dough weight. Use it when adapting a recipe, when switching starter types, or when a dough feels wetter or drier than its stated hydration suggests, which usually means the starter was never counted.
Take 500 g flour, 350 g water and 100 g of starter at 100 percent hydration. Starter flour = 100 × 100 / (100 + 100) = 50 g. Starter water = 100 - 50 = 50 g. Total flour = 500 + 50 = 550 g. Total water = 350 + 50 = 400 g. True hydration = 400 / 550 × 100 = 72.7 percent. Dough weight = 500 + 350 + 100 = 950 g. Notice that ignoring the starter would give 350 / 500 = 70 percent, understating the real hydration by nearly 3 points, enough to change how the dough handles.
Stiff doughs at 50 to 60 percent hydration are firm and easy to shape, good for bagels and sandwich loaves, with a tight, even crumb. The standard range of 65 to 75 percent covers everyday sourdough: manageable stickiness, good oven spring, and a pleasingly open crumb, which is why most beginner recipes land here. High hydration at 80 percent and above gives the wild, irregular holes of artisan loaves but demands confident handling, strong flour, and techniques like stretch-and-folds instead of kneading. Higher is not better, it is just wetter: a well-made 68 percent loaf beats a badly handled 82 percent one every time.
Start beginners at 65 to 72 percent until shaping feels comfortable, then raise the water in small steps. Weigh everything, including the water, since a digital scale beats a measuring jug for repeatability. Remember that wholemeal, rye and strong bread flours absorb more water than plain white flour, so the same percentage feels drier with them. When adjusting an existing recipe toward a target hydration, change only the added water and recalculate: needed water = (target percent / 100 × total flour) - starter water - recipe water. Keep notes on each bake so you learn how your flour and kitchen behave.
Sourdough hydration is the weight of water in your dough divided by the weight of flour, expressed as a percentage. It includes the water and flour already inside your starter, which is why it is called true or total hydration. Most home bakers work between 65 and 80 percent. The number tells you how sticky the dough will be, how fast it ferments, and how open the crumb can get.
Yes, and forgetting it is the most common hydration mistake. A starter at 100 percent hydration is half flour and half water by weight, so 100 g of starter adds 50 g of flour and 50 g of water to your totals. For any other starter hydration, the calculator splits it with the formula starter flour = starter weight × 100 / (100 + starter hydration percent). Leave the starter out and your calculated hydration will read lower than the dough actually is.
Start around 65 to 72 percent. The dough is firm enough to shape without sticking to everything, holds its structure well, and still gives a nice open crumb with good oven spring. Bake that range three or four times until shaping feels easy, then try 73 to 75 percent. There is no prize for jumping straight to 80 percent; technique matters far more than the number.
No, 75 percent is a classic artisan sourdough hydration and very approachable for home bakers. The dough will be sticky and needs gentle handling with stretch-and-folds rather than kneading, plus good gluten development. If it spreads instead of holding shape, your flour may absorb less water than the recipe assumed, so hold back 20 to 30 g of water next time and add it only if the dough feels right.
First calculate your total flour including the flour inside your starter. Then use: water needed = (target hydration / 100 × total flour) - starter water - recipe water. For example, with 550 g total flour at a 75 percent target you need 412.5 g total water; subtract what the starter and recipe already provide and add only the difference. Adjust in small steps and note the result, since flour absorption varies.
Baker's percentage expresses every ingredient as a percentage of the total flour weight, with flour always set to 100 percent. Water at 70 percent means 70 g of water per 100 g of flour; salt is typically 1.8 to 2.2 percent and starter often 10 to 25 percent. Because everything scales off the flour, a formula described this way behaves the same whether you make one loaf or ten, which is why professionals write recipes in percentages.
Above 80 percent, dough becomes slack and sticky by nature: that is the price of an open crumb. Use wet hands and a bench scraper, build strength with coil folds during bulk fermentation, and shape with quick, confident motions. A cold retard in the fridge firms the dough and makes scoring easier. If it still will not hold shape, the flour may be too weak for that hydration, so drop 3 to 5 percent next time.
Use about 2 percent salt by weight of total flour, which is 10 g per 500 g of flour. Below 1.5 percent the bread tastes flat and the dough can turn slack; above 2.5 percent fermentation slows noticeably and the crumb tightens. Salt is one of the few baker's percentages with a genuinely narrow useful range, so weigh it rather than guessing.
Dial in the perfect coffee-to-water ratio for any brew strength.
Find out exactly how long your battery will last under real use.
Double, halve, or resize any recipe with one scale factor.
Find out how long any text takes to read at your own pace.