Coffee Brew Ratio & Extraction Calculator
Dial in a brew by the numbers. Pick a method — each sets a sensible default ratio and target strength — then solve for the water from a dose, the dose from a water weight, or both from a target cup size (the grounds soak up a couple of grams of water per gram of coffee, which this accounts for). Enter a measured TDS and beverage mass and it computes the actual extraction yield and places your brew on the SCA brewing-control chart, telling you whether it is under- or over-extracted and weak or strong. A table maps common ratios to predicted strength for your dose. Espresso is handled as an out:in brew ratio with a note on its different strength scale.
Read the full guide to this tool
Results
Notes
- Extraction yield EY% = beverage mass × TDS ÷ dose. The SCA "Gold Cup" ideal box is 18–22% extraction and 1.15–1.35% strength (TDS) for brewed coffee; under 18% tastes sour, over 22% bitter. Source: SCA brewing-control chart.
- The ratio is water per gram of coffee (a bigger number is a weaker brew). Solving from a cup size accounts for the water the spent grounds retain (~2 g per g of coffee for drip methods).
- Espresso ratio is expressed out:in (yield ÷ dose, e.g. 1:2); its strength runs 8–12% TDS and extraction is measured differently, so the drip SCA bands are not applied to it.
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