Baker's Percentages Explained For Home Bakers

You find a sourdough recipe that looks perfect. It calls for 500g of bread flour, 375g of water, 10g of salt, and 100g of active starter. You want to make half of it. Simple enough. But then you find another recipe that calls for 750g flour, and you want to know if they are basically the same formula. Now you are doing mental math that takes a few minutes and still leaves you unsure.

Baker’s percentages solve exactly this problem. Once you understand the system, you can compare any two formulas at a glance, scale from a single loaf to a bakery run without a calculator, and spot bad recipes before you ever touch a bag of flour.

Flour Is Always 100%

The foundation of the system is this: flour weight always equals 100%, regardless of how much flour there is. Every other ingredient is expressed as a percentage of that flour weight.

This is different from the percentages you learned in school, where percentages are relative to a total. In baker’s math, the percentages of all the ingredients will often add up to more than 100%. That is not an error. It is how the system works.

Take the sourdough example above. 500g of flour is 100%. The 375g of water is 75% of 500g, so hydration is 75%. The 10g of salt is 2% of 500g. The 100g of starter is 20% of 500g.

Written as a formula:

• Flour: 100%
• Water: 75%
• Salt: 2%
• Starter: 20%

That set of percentages is the formula. It tells you everything about that dough’s character regardless of batch size.

Scaling Instantly: The Real Payoff

Here is where the system earns its place. Say you want to make five loaves instead of two. With volumetric measurements, you are recalculating each ingredient separately. With baker’s percentages, you pick a target flour weight and multiply.

Start with the formula above. Two loaves required 500g flour. For five loaves, you might want 1250g of flour. Every other ingredient scales from that number:

• Water: 1250g × 75% = 937.5g
• Salt: 1250g × 2% = 25g
• Starter: 1250g × 20% = 250g

Done. The ratios stay intact no matter the batch size. This is why professional bakers and serious home bakers think in percentages rather than grams.

Going the other direction works just as well. You have 300g of flour left in the bag. Apply the percentages and you know exactly how much of everything else to add for a one-bag batch.

Converting a Volumetric Recipe

Most older recipes and many online sources still use cups and teaspoons. Converting them to baker’s percentages takes three steps.

First, weigh every ingredient to get grams. If a recipe calls for 3 cups of all-purpose flour, measure it and weigh it. A loosely spooned cup of all-purpose flour is around 120g, but packed cups can reach 150g. Weigh it rather than converting from volume, and you get the true number.

Second, set flour to 100%. Whatever the flour weight is, that is your baseline.

Third, divide each other ingredient’s weight by the flour weight and multiply by 100 to get the percentage.

Say a family recipe produces a loaf using 450g flour, 290g water, 9g salt, and 4g instant yeast. Divide each by 450:

• Water: 290 / 450 = 64.4%
• Salt: 9 / 450 = 2%
• Yeast: 4 / 450 = 0.9%

Now you have a formula that will never require converting cups again.

Total Dough Weight and Why It Helps

Once you have your baker’s percentages, you can calculate total dough weight easily. Add up all the percentages: 100% flour + 64.4% water + 2% salt + 0.9% yeast = 167.3% total.

That means every 100g of flour produces 167.3g of finished dough. For the 450g batch: 450 × 1.673 = 752.9g total dough weight.

This matters when you are trying to hit a target. If a recipe calls for a final shaped loaf of 800g, you can work backward from total dough weight (accounting for fermentation loss, around 2%) to figure out exactly how much flour to start with.

The calculator at The Dough Formula handles this math automatically. Enter your flour weight and percentages, and it gives you all ingredient weights plus the total dough weight in one pass.

How Hydration Fits In

Hydration is simply the water percentage in baker’s terms. A 65% hydration dough has 65g of water for every 100g of flour. A 78% hydration dough has 78g of water for every 100g of flour.

Hydration is the percentage bakers talk about most because it has the biggest influence on dough behavior. Higher hydration produces a more open crumb and a thinner crust but makes the dough much harder to shape. Lower hydration gives you a tighter, more manageable dough that holds its form easily.

Knowing the hydration percentage lets you immediately understand what a dough will feel like in your hands, before you have made it even once. If someone tells you they bake a 72% hydration sandwich loaf, you know exactly the kind of dough they are working with.

For a deeper look at hydration ranges and how to choose the right level, see the companion guide Hydration In Bread Dough, From 60% To 90%.

Common Mistakes

Including starter water in the hydration number without accounting for flour. A sourdough starter contains both flour and water. If your starter is 100% hydration (equal weights of flour and water), then 100g of starter contributes 50g of flour and 50g of water to the dough. If you list starter as a separate ingredient and also list all the water, you are double-counting the water in the starter. To calculate true hydration, you must add the water contribution from the starter to the total water, and add the flour contribution from the starter to the total flour, then compute the ratio.

Confusing baker’s percent with percentage of total. If you see that salt is 2% in a formula, that does not mean salt is 2% of the finished dough by weight. It means salt is 2% of the flour weight. The total dough percentage (salt divided by total dough weight) will be slightly lower.

Treating different flours as interchangeable. Baker’s percentages are consistent within a formula, but 75% hydration with a high-protein bread flour will feel very different from 75% hydration with whole wheat or rye. Absorption rates vary by flour type. The percentage tells you the ratio; it does not tell you whether the dough is wet or dry by feel until you know the flour.

Not recording percentages after a successful bake. This is the one that costs bakers the most. You bake a loaf, it comes out perfect, you write down the gram amounts and forget them in a drawer. Three months later you want to scale it up and you have to start over. Record the percentages every time. Grams are batch-specific; percentages are permanent.

Putting It to Work

The fastest way to internalize baker’s percentages is to convert something you already make. Pull out a recipe you know well, weigh every ingredient, set the flour to 100%, and calculate the rest. Then bake it twice using the percentages rather than the original gram amounts. By the second bake you will no longer need to convert; you will think in the ratios directly.

From there, try the Dough Formula calculator to see how it presents formulas in percentage form alongside gram weights. Enter any flour amount and your target percentages, and the gram amounts follow automatically. That workflow, percent-first, is how every serious bread baker operates.

Next up: Hydration In Bread Dough, From 60% To 90% takes the hydration percentage and shows you what it actually means for how your dough handles, shapes, and bakes.