purpose
Espresso Ratio Calculator
Dial in your espresso shots with dose, yield, and ratio calculations. Covers ristretto, normale, and lungo profiles.
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Try an Example
Pick a scenario to see how the calculator works, then adjust the values
Morning Drip Coffee
Two standard cups of medium-strength drip coffee.
Key values: 2 cups (6 oz each) · Medium strength · Arabica beans
Espresso Double Shot
A classic double espresso with standard extraction.
Key values: 18g dose · Normale profile · 25-30 sec pull
Cold Brew Concentrate
A batch of cold brew concentrate for the week.
Key values: 500 mL water · Strong ratio 1:4 · 18-24 hr steep
V60 Pour-Over
A single precise pour-over with bloom calculation.
Key values: 1 cup · Medium-strong · Bloom water shown
What Makes Espresso Different
Espresso forces hot water through finely ground coffee at 9 bars of pressure (about 130 PSI). This high-pressure, short contact time produces a concentrated shot with crema — the golden foam on top composed of emulsified oils and CO₂.
The Espresso Ratio
Espresso uses a brew ratio — the ratio of dry coffee in (dose) to liquid espresso out (yield):
| Style | Ratio | Dose → Yield | Character |
|---|---|---|---|
| Ristretto | 1:1 – 1:1.5 | 18 g → 18–27 g | Intense, syrupy, concentrated |
| Normale | 1:2 | 18 g → 36 g | Balanced, standard |
| Lungo | 1:3 – 1:4 | 18 g → 54–72 g | Lighter, more bitter |
The Dose–Yield–Time Triangle
Three interconnected variables define an espresso shot:
Dose
Grams of dry coffee. Typically 18–20 g for a double shot. Higher dose increases body and intensity.
Yield
Grams of liquid espresso. For a 1:2 ratio with 18 g dose, target 36 g of espresso.
Time
Extraction time: 25–30 seconds. Adjust grind size to hit this window — finer grind = slower, coarser = faster.
Extraction Percentage
Target: extraction, measured with a refractometer. Total dissolved solids (TDS) of well-extracted espresso is typically 8–12%:
Channeling — the most common espresso defect. If water finds a path of least resistance through cracks in the coffee puck, it over-extracts that channel while leaving the rest under-extracted. Even distribution and consistent tamping prevent it.
Frequently Asked Questions
What is the standard espresso brew ratio?
A standard double espresso (normale) uses a 1:2 ratio: 18 g of dry coffee in, 36 g of liquid espresso out, in 25-30 seconds. Ristretto uses 1:1 to 1:1.5 for a more concentrated shot, while lungo uses 1:3 to 1:4 for a lighter, longer extraction.
Why does espresso need 9 bars of pressure?
At 9 bars (about 130 PSI), water is forced through the finely ground coffee puck fast enough to extract flavors in 25-30 seconds while emulsifying oils and CO₂ into crema. Lower pressure under-extracts; higher pressure can cause channeling and bitter over-extraction.
What causes channeling in espresso and how do I fix it?
Channeling occurs when water finds a path of least resistance through cracks in the coffee puck, over-extracting that channel while leaving the rest under-extracted. Fix it by distributing grounds evenly before tamping, using a consistent tamp pressure, and ensuring the correct dose for your basket size.
How do I measure espresso extraction percentage?
Use the formula: . Measure TDS with a refractometer. Well-extracted espresso has 8-12% TDS and 18-22% extraction. Under-extracted espresso tastes sour; over-extracted tastes bitter and astringent.
How do I adjust grind size for espresso?
Grind size is the primary lever for hitting the 25-30 second extraction window. If the shot runs too fast (under 20 seconds), grind finer. If it runs too slow (over 35 seconds), grind coarser. Change by small increments and pull a test shot after each adjustment.
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