Tool
Brew recipe scaler
Scale a coffee dose, water and milk up or down for a different number of servings, with a capacity check.
Scaled recipe
60 g coffee · 960 ml water
4 times the base recipe. The ratio stays at 1:16, so the strength should match the original as long as the extraction does.
- If it tastes different from the original
- If the bigger brew drains slowly or tastes more bitter than the original, grind a little coarser. A deeper bed of coffee holds the water for longer. Do not change the ratio to fix it.
- Keep the same
- The ratio, the coffee and the water temperature. If the recipe has a bloom or timed pours, scale their amounts by the same factor.
- What this cannot tell you
- The arithmetic is exact. Whether the result tastes like the original is not: extraction shifts with batch size, bed depth and the shape of the brewer, and this tool cannot predict by how much.
Exact arithmetic on your numbers
What to do with the result
- The ratio you are scaling is not yet the one you want: Coffee-to-water ratio calculator
- You are filling a batch brewer or a flask: Batch brew calculator
- You want the starting recipe your brewer's page gives, to check the scaled one against: Brewing methods: a starting point for each brewer
- The larger or smaller brew runs or tastes differently from the original: Make my coffee better
How it works
Everything is multiplied by the ratio between the servings you want and the servings the recipe was written for. The capacity check then compares the scaled water against the brewer range you give it, because a number that scales correctly can still be more than the brewer holds.
What the inputs mean
- Base servings
- How many servings the recipe you are starting from produces.
- Brewer capacity
- The usable range of your brewer in cups, which is not always what the packaging claims. Both the minimum and the maximum matter.
Worked examples
Doubling a French press recipe
- Base 1 serving: 17 g coffee, 280 g water
- Target 2 servings
Result: 34 g coffee, 560 g water.
Common mistakes
Scaling a single-cup pour-over recipe to a litre unchanged
A deeper bed drains more slowly and extracts differently. Expect to grind a little coarser as the batch grows.
Scaling below a brewer's minimum
A brewer running well under its minimum leaves too shallow a bed and channels. The capacity check flags this.
What the result does not mean
- A scaled recipe is a starting point, not the same brew at a different size. Contact time changes with batch size even when the ratio does not.
- The tool tells you which way to move the grind if the scaled brew tastes different. It cannot tell you by how much.
What this does not account for
- Scales dose and water linearly by servings — real extraction does not always scale perfectly linearly with bed depth and brewer geometry.
- The capacity check compares against the range you enter, not a specific product's exact limit.