How to Calculate Baker's Percentage: Step-by-Step Guide

Published: January 19, 2026 | 5 min read | Baker's Math Tutorial
Baker's percentage calculator tutorial showing step-by-step how to calculate flour and water ratios

Baker's percentage is the foundation of professional bread baking. Whether you're making sourdough, pizza dough, or enriched breads, understanding baker's math will transform how you bake. This guide will teach you exactly how to calculate baker's percentage in just a few simple steps.

What is Baker's Percentage?

Baker's percentage (also called baker's math or baker's formula) is a system where flour is always 100%, and all other ingredients are expressed as percentages of the total flour weight. This makes recipes infinitely scalable and easier to understand.

Unlike regular percentages where everything adds up to 100%, baker's percentages can total well over 100% because each ingredient is calculated independently relative to flour.

The Baker's Percentage Formula

Baker's Percentage = (Ingredient Weight ÷ Total Flour Weight) × 100 Example: Water % = (700g water ÷ 1000g flour) × 100 = 70%

This formula works for every ingredient in your recipe: water, salt, yeast, eggs, butter, and everything else.

Step-by-Step: How to Calculate Baker's Percentage

  1. Set Your Flour to 100%

    Start by identifying the total flour weight in your recipe. This becomes your 100% baseline. If you're using multiple types of flour, add them together.

    Example:

    800g bread flour + 200g whole wheat = 1000g total flour (100%)

  2. Apply the Formula to Each Ingredient

    Divide each ingredient's weight by the total flour weight, then multiply by 100.

    Example with 1000g flour:

    • Water 700g: (700 ÷ 1000) × 100 = 70%
    • Salt 20g: (20 ÷ 1000) × 100 = 2%
    • Yeast 10g: (10 ÷ 1000) × 100 = 1%
  3. Write Your Baker's Formula

    Express the complete recipe as percentages. This format is universal and infinitely scalable.

    Result:

    Flour 100% | Water 70% | Salt 2% | Yeast 1%

    Total: 173% (this is normal - baker's percentages don't add to 100%)

  4. Scale to Any Size

    To scale, simply multiply each percentage by your desired flour weight.

    Example: Double the recipe (2000g flour)

    • Flour: 2000g × 100% = 2000g
    • Water: 2000g × 70% = 1400g
    • Salt: 2000g × 2% = 40g
    • Yeast: 2000g × 1% = 20g

Quick Reference: Common Percentages

Once you understand the formula, these typical ranges will help you evaluate and create recipes:

Hydration Levels by Bread Type

Bread Type Hydration Dough Feel
Bagels55-60%Stiff, easy to shape
Sandwich bread60-65%Soft, manageable
Sourdough70-75%Tacky, requires folding
Pizza (traditional)60-70%Extensible, smooth
Ciabatta80-85%Very wet, sticky

Standard Ingredient Ranges

Ingredient Typical % Notes
Salt1.8-2.5%2% is standard
Instant yeast0.5-1%Less for slow fermentation
Sourdough starter10-20%Higher = faster rise
Sugar2-10%Depends on bread type
Butter/Oil3-20%Higher for enriched doughs

Practical Example: 70% Hydration Sourdough

Let's calculate baker's percentage for a classic sourdough bread recipe from scratch.

Recipe Ingredients:

  • Bread flour: 1000g
  • Water: 700g
  • Salt: 20g
  • Sourdough starter (100% hydration): 200g

Calculating Baker's Percentages:

  1. Flour: 1000g = 100% (always)
  2. Water: (700 ÷ 1000) × 100 = 70%
  3. Salt: (20 ÷ 1000) × 100 = 2%
  4. Starter: (200 ÷ 1000) × 100 = 20%

Baker's Formula: Flour 100% | Water 70% | Salt 2% | Starter 20%

Total Percentage: 192% (This is normal! Percentages don't need to add to 100%)

Working Backwards: From Target Dough Weight

Sometimes you know how much dough you need (for example, 2000g for two loaves) and want to calculate ingredient weights. Here's how:

Example: Calculate ingredients for 2000g of 70% hydration dough

Step 1: Add up all percentages

100% (flour) + 70% (water) + 2% (salt) + 1% (yeast) = 173%

Step 2: Calculate flour weight

Flour = 2000g ÷ 1.73 = 1156.1g

Step 3: Calculate other ingredients

  • Flour: 1156.1g (100%)
  • Water: 1156.1g × 0.70 = 809.2g (70%)
  • Salt: 1156.1g × 0.02 = 23.1g (2%)
  • Yeast: 1156.1g × 0.01 = 11.6g (1%)

Total dough weight: 1156.1 + 809.2 + 23.1 + 11.6 = 2000g ✓

Common Mistakes to Avoid

1. Forgetting to Account for Flour in Starter

If you're using sourdough starter, remember it contains both flour and water. A 100% hydration starter (most common) is 50% flour and 50% water. Advanced bakers account for this in their calculations.

2. Mixing Up Percentages and Grams

Always clarify whether you're working with percentages or weights. "70% water" means the weight of water is 70% of flour weight, not 70% of total dough.

3. Not Considering Flour Types

Different flour types absorb water differently. Whole wheat flour typically needs 5-10% higher hydration than white flour for the same dough consistency.

Why Use a Baker's Percentage Calculator?

While the math is straightforward, calculating baker's percentages manually for complex recipes (especially with preferments, multiple flours, and enrichments) can be time-consuming and error-prone.

A dedicated baker's percentage calculator helps you:

Skip the Math

Flourwise calculates baker's percentages automatically, handles preferments, and scales recipes instantly.

Get on Google Play Android only • Free

Advanced: Hydration with Preferments

When using preferments (poolish, biga, or sourdough starter), calculating true hydration gets more complex because the preferment contains both flour and water.

Example: Sourdough with 100% Hydration Starter

Recipe:

  • Bread flour: 1000g (100%)
  • Water: 650g (65%)
  • Sourdough starter (100% hydration): 200g (20%)

Breaking down the starter:

  • Starter flour: 100g (50% of 200g starter)
  • Starter water: 100g (50% of 200g starter)

True totals:

  • Total flour: 1000g + 100g = 1100g
  • Total water: 650g + 100g = 750g
  • True hydration: (750 ÷ 1100) × 100 = 68.2%

This is why many bakers use a calculator for recipes with preferments - the math gets complicated quickly!

Conclusion

Baker's percentage is an essential skill for any serious home baker. Once you understand the simple formula - everything relative to flour weight at 100% - you can scale recipes infinitely, adjust hydration with confidence, and truly understand how recipes work.

Start practicing with simple recipes, and soon baker's math will become second nature. For complex calculations or when you need speed, use a dedicated baker's percentage calculator to handle the heavy lifting.

Frequently Asked Questions

What is baker's percentage?

Baker's percentage (also called baker's math) is a notation method where flour is always 100%, and all other ingredients are expressed as a percentage of the total flour weight. For example, 70% hydration means water weighs 70% of the flour weight.

Why do baker's percentages add up to more than 100%?

Unlike regular percentages, baker's percentages don't represent parts of a whole. Each ingredient is calculated independently relative to flour. A recipe with 100% flour, 70% water, and 2% salt totals 172% - and that's correct.

What is a good hydration level for bread?

It depends on the bread type. Bagels use 55-60%, sandwich bread 60-65%, sourdough 70-75%, and ciabatta 80-85%. Higher hydration creates more open crumb but is harder to handle.

How do I calculate baker's percentage from a recipe?

Divide each ingredient's weight by the total flour weight, then multiply by 100. For example: 700g water ÷ 1000g flour × 100 = 70% hydration.