Cooking & Baking · Baking Ratios & Measurements

Baker’s Percentage & Hydration Model

Calculate baker’s percentages, bread hydration and total dough weight from ingredient weights. Include multiple flours and a starter or pre-ferment, then calculate water for a target hydration or scale the formula to a new flour amount.

Scale a recipe by serving size Convert kitchen measurements Convert weight units

Enter your dough formula

Keep ingredient weights in one selected unit. Flour is the 100% reference for baker’s percentage calculations.

Scales the complete formula while preserving its current baker’s percentages.
Extra flour types Included in total flour
Starter / pre-ferment Optional. Enter its flour and water separately so both can contribute correctly to total flour and hydration.
Other ingredients Optional baker’s percentages
Tool description Calculates baker’s percentages, dough hydration and formula scaling.
Tool type Baking ratio & dough formulation calculator
Core logic Total flour → ingredient ratios → hydration → target scaling
Purpose Analyze and scale bread or dough formulas by weight.
Method: Define→ Validate→ Normalize→ Calculate→ Check→ Present Calculation methodology

Formula & methodology

How Baker’s Percentage and Dough Hydration Are Calculated

Baker’s percentage expresses every ingredient relative to the total flour weight. Flour is the 100% reference, while water, salt, yeast, starter components and other ingredients are calculated as percentages of that flour weight. The same ratios can then be used to analyze hydration or scale the formula.

Define Identify flour and ingredients
Validate Check weights and units
Normalize Use compatible weight units
Calculate Divide by total flour
Check Verify totals and ratios
Present Round display values

1. Governing baker’s percentage equations

Unlike percentages where all components must add to 100%, baker’s percentage uses total flour as the fixed reference. Consequently, the percentages of all ingredients in a dough formula can add to more than 100%.

Flour reference Flour % = 100%

Total flour weight is the denominator for the ingredient percentages.

Ingredient percentage I% = (Wᵢ ÷ F) × 100

In words: ingredient weight ÷ total flour weight × 100.

Dough hydration H% = (W ÷ F) × 100

Total water weight ÷ total flour weight × 100.

Salt percentage S% = (S ÷ F) × 100
Yeast percentage Y% = (Y ÷ F) × 100
Important: hydration is a flour-relative ratio. A dough containing 500 g flour and 350 g water has 70% hydration because 350 ÷ 500 × 100 = 70%. It does not mean that water represents 70% of the total dough weight.

2. Variables and definitions

Symbol Variable Meaning Unit
F Total flour weight All flour in the formula, including flour contained in a starter or pre-ferment. Weight
W Total water weight Added water plus water contained in a starter or pre-ferment. Weight
Wᵢ Ingredient weight Weight of the individual ingredient whose baker’s percentage is being calculated. Weight
I% Ingredient percentage Ingredient weight expressed relative to total flour. %
H% Hydration Total water expressed as a percentage of total flour. %
S Salt weight Weight of salt in the dough formula. Weight
Y Yeast weight Weight of yeast entered in the formula. Weight
D Total dough weight Sum of all ingredient weights after starter components are accounted for once. Weight
k Scale factor Ratio used to scale the complete formula to a new total flour weight. Dimensionless

3. Calculate total flour and total water first

When several flour types are used, they are combined before baker’s percentages are calculated.

Total flour F = F₁ + F₂ + ... + Fₙ + Fₚ

Fₚ represents flour contained in a starter or pre-ferment.

Total water W = Wₐ + Wₚ

Added water plus water contained in the pre-ferment.

Calculation order: determine total flour and total water before calculating hydration. This prevents starter flour from being omitted from the denominator or starter water from being omitted from the numerator.

4. How starter and pre-ferment are handled

A starter cannot be treated as one undifferentiated ingredient when calculating true dough hydration because it normally contributes both flour and water.

Flour in starter Ftotal = Fmain + Fextra + Fstarter

Starter flour increases the flour reference used for every baker’s percentage.

Water in starter Wtotal = Wadded + Wstarter

Starter water increases the total water used in the hydration calculation.

Example with a starter

Suppose a dough contains 450 g main flour, 300 g added water and a starter containing 50 g flour plus 50 g water.

Total flour F = 450 + 50 = 500 g
Total water W = 300 + 50 = 350 g
Hydration H% = 350 ÷ 500 × 100 = 70%
If only the total starter weight is known but its flour/water composition is unknown, the calculator does not have enough information to determine its exact contribution to hydration.

5. Weight-unit normalization

Ratios are valid when numerator and denominator use compatible weight units. The calculator’s main interface keeps the formula in one selected weight unit, avoiding unnecessary conversions inside the ratio.

Conversion Equation Use
Kilograms → grams g = kg × 1,000 Metric weight normalization
Grams → kilograms kg = g ÷ 1,000 Metric display conversion
Ounces → grams g = oz × 28.349523125 US/metric normalization
Pounds → ounces oz = lb × 16 US customary normalization
Pounds → grams g = lb × 453.59237 US/metric normalization
For example, 350 g ÷ 500 g and 0.350 kg ÷ 0.500 kg both produce the same ratio, 0.7. Do not divide values expressed in different units without first converting them to compatible units.

For standalone conversions, use the Mass & Weight Conversion Tool or the Culinary & Kitchen Measurement Converter .

6. Calculate water for a target hydration

The hydration equation can be rearranged when total flour and a desired hydration percentage are known.

Target total water Wtarget = F × (Htarget ÷ 100)

Total flour × target hydration as a decimal.

Without starter water Wadded = Wtarget
With starter water Wadded = Wtarget − Wstarter

Example

With 500 g total flour and a target hydration of 75%:

Substitution Wtarget = 500 × (75 ÷ 100) = 375 g

If the dough already contains 50 g of water inside a starter, the separately added water required would be:

Starter adjustment Wadded = 375 − 50 = 325 g

7. Scale a baker’s percentage formula

A formula can be scaled to a new total flour amount while preserving its ingredient percentages.

Scale factor k = Ftarget ÷ Fcurrent
Scaled ingredient Wnew = Wcurrent × k
Alternative from percentage Wᵢ = Ftarget × (I% ÷ 100)

An ingredient’s weight can also be reconstructed directly from its baker’s percentage.

Default formula scaled to 1,000 g flour

Ingredient Baker’s % 500 g flour formula 1,000 g flour formula
Flour 100% 500 g 1,000 g
Water 70% 350 g 700 g
Salt 2% 10 g 20 g
Yeast 1% 5 g 10 g
Total dough 173% 865 g 1,730 g
Here, k = 1,000 ÷ 500 = 2. Each ingredient is multiplied by 2, so the ingredient ratios and 70% hydration remain unchanged.

8. How to calculate baker’s percentage manually

The same method can be reproduced without the calculator.

Basic dough without a starter
  1. Add all flour weights to determine total flour F.
  2. Treat that total flour as 100%.
  3. For each ingredient, calculate ingredient weight ÷ total flour × 100.
  4. For hydration, calculate water ÷ total flour × 100.
  5. Add all ingredient weights to obtain total dough weight.
  6. Keep full calculation precision and round only the displayed percentages.
Dough containing multiple flour types
  1. Add every flour: F = F₁ + F₂ + ... + Fₙ.
  2. Use the combined flour weight as the 100% denominator.
  3. Calculate each individual flour’s percentage against that same total if a flour breakdown is required.
  4. Calculate water, salt, yeast and other ingredients against the combined flour weight.
Dough containing a starter or pre-ferment
  1. Determine how much flour the starter contributes.
  2. Determine how much water the starter contributes.
  3. Add starter flour to the other flour weights.
  4. Add starter water to the other water.
  5. Calculate hydration from those two combined totals: H% = total water ÷ total flour × 100.
  6. Do not add the starter’s total weight again when calculating dough weight; its flour and water have already been counted.

9. Default calculation breakdown

Using the calculator’s default example: 500 g flour, 350 g water, 10 g salt and 5 g yeast.

  1. Input values Flour = 500 g; water = 350 g; salt = 10 g; yeast = 5 g
  2. Normalized values All ingredient weights already use grams. Total flour = 500 g and total water = 350 g.
  3. Formula H% = (W ÷ F) × 100
  4. Substitution H% = (350 ÷ 500) × 100
  5. Intermediate calculation 350 ÷ 500 = 0.7
  6. Raw result 0.7 × 100 = 70
  7. Displayed result 70.0% hydration
Precision rule: calculations should retain full numeric precision internally. Rounding is applied to displayed values, not unnecessarily to intermediate calculations.

Featured Article

Worked examples & interactive analysis

Baker’s Percentage Examples and Hydration Comparison

See how a bread formula is converted into baker’s percentages, then test how changing hydration alters the required water and total dough weight while the flour basis and other ingredient percentages remain unchanged.

Worked example: a two-flour bread dough with starter

This example shows why starter flour and starter water must be separated before hydration is calculated.

Example situation

A home baker is developing a bread formula containing bread flour, whole-wheat flour and a liquid starter. They want the true hydration, the baker’s percentage of each ingredient and the total dough weight.

Main bread flour 400 g
Whole-wheat flour 50 g
Starter composition 50 g flour + 50 g water
Added water 325 g
Salt 10 g
Yeast 0 g
Total flour F = 400 + 50 + 50 = 500 g
Total water W = 325 + 50 = 375 g
Hydration H% = 375 ÷ 500 × 100 = 75%
The calculation says: the dough contains 500 g total flour and 375 g total water, giving 75% hydration and 885 g total dough weight.
This may mean: the formula has more water relative to flour than the 70% default example. Dough handling can differ, but hydration alone does not determine how loose, sticky or extensible a dough will feel.
Worked baker’s percentage calculation
Ingredient / component Weight Calculation Baker’s %
Bread flour 400 g 400 ÷ 500 × 100 80%
Whole-wheat flour 50 g 50 ÷ 500 × 100 10%
Flour in starter 50 g 50 ÷ 500 × 100 10%
Total flour 500 g 400 + 50 + 50 100%
Added water 325 g 325 ÷ 500 × 100 65%
Water in starter 50 g 50 ÷ 500 × 100 10%
Total water / hydration 375 g 375 ÷ 500 × 100 75%
Salt 10 g 10 ÷ 500 × 100 2%
Total dough 885 g 500 + 375 + 10 177%*
*177% is the total formula expressed relative to flour: 100% flour + 75% water + 2% salt. Baker’s percentages are flour-relative and therefore do not need to sum to 100%.
Starter check Starter = 50 g flour + 50 g water = 100 g total starter

The 100 g starter is not added again to total dough weight: its 50 g flour and 50 g water have already been counted.

Compare hydration scenarios

Holding total flour at 500 g and salt at 2%, each 5 percentage-point increase in hydration adds 25 g of water.

Scenario A 65% hydration
Total flour
500 g
Total water
325 g
Salt at 2%
10 g
Total dough
835 g
Scenario B 70% hydration
Total flour
500 g
Total water
350 g
Salt at 2%
10 g
Total dough
860 g
Scenario C 75% hydration
Total flour
500 g
Total water
375 g
Salt at 2%
10 g
Total dough
885 g

Hydration & Formula Sensitivity Explorer

Hold the flour basis and non-water ingredients constant, then change hydration to see exactly how much total water and dough weight change.

Set a comparison formula

This explorer analyzes hydration sensitivity. It does not replace the full baker’s percentage calculator above.

75.0%
Total water at comparison hydration 375 g

500 g flour × 75% = 375 g water

Baseline water 350 g
Water difference +25 g
Salt weight 10 g
Yeast weight 5 g
Baseline dough weight 865 g
Comparison dough weight 890 g
Water formula W = 500 × (75 ÷ 100) = 375 g
Baseline and comparison hydration formulas
Metric Baseline Comparison Change
Hydration 70.0% 75.0% +5.0 points
Total water 350 g 375 g +25 g
Total dough 865 g 890 g +25 g
The calculation says

Increasing hydration from 70.0% to 75.0% requires 25 g more water for 500 g flour.

This may mean

The comparison formula contains more water relative to flour. Actual dough handling still depends on flour, ingredients and process.

Tool description Tests how a hydration change affects water and dough weight.
Tool type Hydration sensitivity explorer
Core logic Flour × hydration → water → revised dough weight
Purpose Isolate hydration changes without rebuilding the full formula.
Baker’s Percentage & Hydration Model Recipe Scaling & Serving Size Calculator Culinary & Kitchen Measurement Converter Calculation methodology

Understanding your results

Baker’s Percentage and Hydration Reference Guide

Baker’s percentages make bread formulas easier to compare and scale, but the numbers describe ingredient ratios rather than guaranteeing a particular dough texture or baking result. Use the calculated percentages as a consistent formula framework, then interpret them in the context of the flour, ingredients and process being used.

How to interpret baker’s percentage

Baker’s percentage sets the total flour weight to 100%. Every other ingredient is expressed relative to that flour amount rather than as a share of the entire dough.

The calculation says

If 500 g of total flour is paired with 350 g of total water, hydration is 70% because 350 ÷ 500 × 100 = 70%. If salt weighs 10 g, salt is 2% because 10 ÷ 500 × 100 = 2%.

This may mean

The formula contains a particular amount of water, salt or another ingredient relative to its flour. How the dough actually handles or bakes also depends on ingredient properties and process variables.

Do not read baker’s percentage like nutritional or composition percentage. A formula containing 100% flour, 70% water, 2% salt and 1% yeast totals 173 baker’s percentage points. That is valid because flour is the reference denominator.

What dough hydration measures

Dough hydration is the ratio of total water to total flour, expressed as a percentage.

Hydration H% = (total water ÷ total flour) × 100
Water from target hydration W = total flour × (Htarget ÷ 100)

For example, 500 g total flour at 70% hydration requires 350 g total water. At 75%, the same flour basis requires 375 g total water.

Hydration is a mathematical ratio, not a complete description of dough consistency. Two doughs with the same calculated hydration can behave differently because their flour and other ingredients may absorb or bind water differently.

Hydration comparison reference

The table below is best used as a mathematical comparison of water-to-flour ratios. The qualitative descriptions are broad orientation only, not rigid bread-style classifications.

Hydration Water per 500 g flour Water per 1,000 g flour General ratio interpretation
50% 250 g 500 g 0.50 units of water for every 1 unit of flour.
55% 275 g 550 g 0.55 units of water for every 1 unit of flour.
60% 300 g 600 g 0.60 units of water for every 1 unit of flour.
65% 325 g 650 g 0.65 units of water for every 1 unit of flour.
70% 350 g 700 g 0.70 units of water for every 1 unit of flour.
75% 375 g 750 g 0.75 units of water for every 1 unit of flour.
80% 400 g 800 g 0.80 units of water for every 1 unit of flour.
90% 450 g 900 g 0.90 units of water for every 1 unit of flour.
100% 500 g 1,000 g Equal flour and water weights.
For a fixed flour weight, every increase of 1 hydration percentage point adds water equal to 1% of the flour weight. With 500 g flour, one percentage point equals 5 g water; with 1,000 g flour, it equals 10 g.

Multiple flour types still share one 100% flour basis

When a formula contains several flour types, add their weights before calculating hydration or other baker’s percentages. Individual flour percentages can then describe the flour blend.

Flour Weight Calculation Flour-basis %
Bread flour 400 g 400 ÷ 500 × 100 80%
Whole-wheat flour 50 g 50 ÷ 500 × 100 10%
Flour in starter 50 g 50 ÷ 500 × 100 10%
Total flour 500 g 400 + 50 + 50 100%

In this example, all flour components together establish the denominator. Calculating hydration against only the 400 g bread flour would overstate the true water-to-total-flour ratio.

Starter and pre-ferment considerations

A starter or pre-ferment may contain both flour and water. For dough hydration, those components need to be allocated to their respective totals.

Total flour F = main flour + extra flour + starter flour
Total water W = added water + starter water

Example: 100% hydration starter

If a 100 g starter contains equal weights of flour and water, it contributes 50 g flour and 50 g water to the dough.

The starter’s 100 g total weight should not then be added again when computing total dough weight. Its 50 g flour and 50 g water have already accounted for the full 100 g.
Unknown starter composition: knowing that a formula contains 100 g of starter is not enough to calculate exact total hydration unless the starter’s flour and water composition is also known.

Assumptions behind the model

  • Weight-based formulation: ingredient quantities are modeled by weight rather than by cups, tablespoons or other volume measures.
  • Common flour denominator: all flour components that are intended to count as flour in the formula are included in total flour.
  • Water allocation: water identified inside a starter or pre-ferment is included in total water.
  • Compatible units: numerator and denominator use the same or correctly converted weight units before a ratio is calculated.
  • Scaling preserves ratios: when a complete formula is scaled by one factor, its baker’s percentages remain unchanged.
  • Displayed rounding: intermediate arithmetic retains full available precision; formatting and rounding are applied to displayed results.

Limitations of a hydration calculation

Hydration is useful for describing a formula, but it is not a complete physical model of dough behavior.

Flour characteristics

Flour type, protein characteristics, milling and other properties can affect how a dough responds to a given amount of water. Equal calculated hydration therefore does not guarantee equal handling.

Other water-containing ingredients

The calculator’s hydration value is based on the water explicitly modeled as water, including supported starter water. Ingredients that contain their own moisture can complicate comparisons if that moisture is not separately represented in the formula.

Other ingredients and dough structure

Salt, fats, sugars, eggs, dairy and other additions may affect dough behavior. Their baker’s percentages are useful formula descriptors, but a simple hydration ratio does not model every interaction among ingredients.

Mixing, fermentation and temperature

The numerical formula does not model mixing development, fermentation schedule, dough temperature, rest periods, shaping technique or baking conditions.

Rounding and very small formulas

Scaling can produce ingredient quantities that are difficult to measure accurately with ordinary kitchen equipment. This is especially relevant for small amounts of yeast, salt or other low-percentage ingredients.

Common baker’s percentage mistakes

Using total dough as the denominator

Baker’s percentage divides ingredient weight by total flour, not by total dough weight.

Expecting percentages to total 100%

Flour alone is defined as 100%, so the complete formula normally totals more than 100%.

Ignoring extra flour types

Bread flour, whole-grain flour and other included flours should be combined into the total flour basis.

Ignoring starter flour

Leaving starter flour out of the denominator can overstate calculated hydration and other ingredient percentages.

Ignoring starter water

Leaving starter water out of total water can understate calculated hydration.

Double-counting starter

After starter flour and water are allocated, do not also add the full starter weight again to total dough.

Mixing incompatible units

A ratio such as grams ÷ ounces is invalid until both weights have been normalized to compatible units.

Rounding too early

Repeatedly rounding intermediate values can introduce avoidable scaling differences.

Why baker’s percentage is useful for scaling

Once ingredient ratios are expressed relative to flour, the formula can be reconstructed at another flour quantity without changing those ratios.

From percentage ingredient weight = target flour × (ingredient % ÷ 100)
Using a scale factor k = target flour ÷ current flour
Ingredient Baker’s % 500 g flour 750 g flour 1,000 g flour
Flour 100% 500 g 750 g 1,000 g
Water 70% 350 g 525 g 700 g
Salt 2% 10 g 15 g 20 g
Yeast 1% 5 g 7.5 g 10 g
Total dough 173% 865 g 1,297.5 g 1,730 g
Scaling changes ingredient weights but not their baker’s percentages. A 70% hydration formula remains 70% hydration when every component is scaled consistently.