Baker's Percentages Demystified: A Practical Calculator Guide

Short answer: baker's percentage expresses each ingredient as a percentage of total flour weight. 100% flour, 75% water (75g per 100g flour), 20% starter, 2% salt. Once you understand it, you can scale and adjust any recipe.

Why baker's percentages matter

Baker's percentages let you:

• Scale recipes (1 loaf to 10 loaves)
• Compare recipes across sources
• Adjust hydration easily
• Develop your own recipes
• Communicate clearly with other bakers

It's the universal language of bread.

The basic formula

Flour is always 100%. Other ingredients are percentages of the flour:

For a 500g flour recipe:

• Flour: 500g (100%)
• Water: 350g (70%)
• Starter: 100g (20%)
• Salt: 10g (2%)

Why flour is always 100%

Flour is the base. Everything else relates to it.

If you have 500g flour, water at 70% means 350g water. Salt at 2% means 10g salt.

This makes scaling easy: just multiply.

Multiple flours

If your recipe uses multiple flours, sum them:

• 400g bread flour + 100g whole wheat = 500g total flour (100%)
• Water at 70% = 350g

The percentages still relate to total flour.

A worked example

Recipe in baker's % :

• Flour: 100% (mixed)
• Water: 75%
• Starter: 20%
• Salt: 2%

For 1kg of dough:

• Total dough = flour + water + starter + salt
• 1kg = 100% + 75% + 20% + 2% = 197% total
• Flour = 1000g / 1.97 = 508g
• Water = 508 × 0.75 = 381g
• Starter = 508 × 0.20 = 102g
• Salt = 508 × 0.02 = 10g

Verify: 508 + 381 + 102 + 10 = 1001g (close enough)

Scaling a recipe

Original recipe: 500g flour, 350g water, 100g starter, 10g salt.

Want to make 2 loaves? Double everything:

• 1000g flour, 700g water, 200g starter, 20g salt

Want to make 1.5x? Multiply by 1.5:

• 750g flour, 525g water, 150g starter, 15g salt

Easy.

Adjusting hydration

To change a recipe from 70% to 75% hydration:

• Keep flour the same (500g)
• Change water: 500 × 0.75 = 375g (instead of 350g)

That's it. The recipe is now 75% hydration.

A starter has hydration too

A 100% hydration starter (50/50 flour and water by weight) contributes both flour and water.

100g starter at 100% hydration = 50g flour + 50g water.

For precision, factor this into total flour and water:

• Total flour = recipe flour + starter flour
• Total water = recipe water + starter water

For most home bakers, this nuance can be ignored without dramatic effect.

A 2% salt rule

Salt at 2% of flour weight is the standard.

• Below 1.5%: bland
• 1.8–2.2%: ideal range
• Above 2.5%: noticeably salty

Stick with 2%.

Inclusions don't count

Olives, nuts, raisins, cheese:

• Are NOT factored into total flour
• Add weight to the dough
• Don't affect baker's % calculations

So a recipe with 100g cheese still has 500g flour (100%).

A recipe template

Use this format for any sourdough recipe:

Adjust grams by changing the 500g base.

Why percentages beat cups

Cups vary:

• Aerated flour vs scooped flour: 20% difference
• Different flours have different densities
• Inconsistent across bakers

Percentages are universal:

• A grams scale doesn't lie
• 75% hydration in Tokyo is 75% in New York
• Recipes are reproducible

Always weigh, never measure by volume.

Common percentages by bread style

These are guidelines. Your specific flour determines what's possible.

A flour conversion

If a recipe says 500g and you have 600g of dough you need to use:

• Total dough is 197% (recipe % sum)
• 600g / 1.97 = 305g flour needed
• Adjust other ingredients proportionally

Useful when you have a finite amount of starter or want to use up flour.

A recipe spreadsheet

For multiple recipes, use a spreadsheet:

• Column A: ingredient
• Column B: percentage
• Column C: =B × $D$1 (where D1 is your flour weight)

Change the flour weight in D1; everything else updates.

Scaling for different shapes

For a 1kg boule: 500g flour For two 500g boules: same total, two pieces For a sheet pan focaccia: ~700g flour For 12 burger buns: ~500g flour

Adjust based on the bread; the percentages stay the same.

When percentages don't apply

Some recipes (enriched, sweet) might use:

• Sugar at 5–10%
• Butter at 5–15%
• Eggs by weight

These all relate to flour. Same logic applies.

A practical use

A baker's percentage cheat sheet:

• 500g flour = 1 standard loaf
• 1000g flour = 2 loaves or 1 large
• 250g flour = small loaf or rolls
• 100g flour = practice batch

Once you know flour weight, everything else scales by percentage.

Final note

Baker's percentages take 30 minutes to learn but pay dividends forever.

After a week of using them, you'll never go back to cup measurements. Your bakes will be more consistent. Recipe development becomes easy.

It's the single most useful tool in serious bread baking.