Baker's Percentage Converter

How to use this calculator

Pick a mode at the top of the form. Weights → % takes an existing recipe’s gram weights and converts them to baker’s percentages. This is useful when you find a recipe online and want to understand its ratios, compare it to another formula, or save it in a format you can scale later. % → Weights does the reverse — enter a baker’s formula as percentages along with your target flour weight, and the calculator outputs exact gram weights for every ingredient. Both modes account for the flour and water inside your starter.

What baker’s percentage is and why it matters

Baker’s percentage is the standard notation for bread formulas. Flour is always 100%. Every other ingredient is expressed as a percentage of the total flour weight. A recipe with 500g flour and 375g water is 75% hydration. Salt at 10g is 2%. Starter at 100g is 20%.

The system exists because it makes recipes scale-independent. A formula that reads “75% hydration, 2% salt, 20% starter” tells you exactly how the dough will feel and ferment regardless of whether you are making 500g of flour or 5kg. You do not need to recalculate from scratch when you change batch size — just multiply everything by your flour target. Professional bakers worldwide communicate in baker’s percentages for exactly this reason. It is the universal language of bread.

Why starter matters in the calculation

A sourdough starter is not a single ingredient — it is a mixture of flour and water with a living culture. A 100g starter at 100% hydration contains 50g flour and 50g water. If you ignore this and treat the starter as a separate thing, your actual hydration and your actual flour total will both be wrong.

This calculator splits the starter into its flour and water components before computing percentages. In forward mode, the hydration you see reflects the true water-to-flour ratio in your dough, not the naive version. In reverse mode, the “recipe flour” output is the flour you actually need to weigh out — the rest is already in your starter. If you want more detail on this split, our hydration calculator shows the breakdown step by step.

Common percentages by bread type

These are starting points, not rules. Flour varies, preferences differ, and your kitchen is not the same as someone else’s. But they give you a frame of reference when building or evaluating a formula.

Country sourdough loaf: 68–75% hydration, 2% salt, 20% starter. The workhorse artisan loaf. Balanced crumb, good oven spring, manageable shaping.

High-hydration open crumb: 78–85% hydration, 2% salt, 15–20% starter. Ciabatta and focaccia territory. Wet, extensible dough that rewards patience and wet hands.

Sandwich bread: 58–65% hydration, 2% salt, 15% starter. Plus enrichments: 5–10% butter or oil, 5–8% sugar. Tight, soft crumb for slicing.

Bagels: 50–58% hydration, 2% salt, 20% starter. Very stiff dough that holds its shape through boiling. Often includes 5–10% malt syrup.

Pizza dough: 62–70% hydration, 2.5–3% salt, 10–15% starter. Slightly higher salt for flavor, lower starter for a slower rise that develops complexity.

From percentages to a bake

Here is the practical workflow. Find a formula you like — from a book, another baker, or your own notes. Enter the percentages in reverse mode with your target flour weight. The calculator outputs exact weights. Weigh your ingredients. Mix. The starter feeding calculator can help you get your starter ready on schedule, and the hydration calculator can double-check the water ratio once everything is in the bowl.

A note on precision: baker’s percentage is accurate to the degree your scale is. A scale that reads to 1g is fine for flour and water; salt benefits from 0.1g precision if you bake small batches. Do not stress about hitting 72.0% versus 72.3% — the dough will not notice, and neither will you.