Coffee Ratio Calculator

This coffee ratio calculator converts grams of coffee to milliliters of water (and vice versa) using your chosen brew strength. The golden ratio is 1:16 — 20g of coffee needs 320 ml of water, giving approximately 1.35 cups. Strong brews use 1:15; mild brews use 1:17.

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Frequently Asked Questions

What is the golden ratio for coffee?

The Specialty Coffee Association (SCA) recommends a brew ratio of 1:15 to 1:18, meaning 1 gram of coffee for every 15–18 ml of water. The most popular general-purpose ratio is 1:16: 1 gram of coffee per 16 ml of water, which gives a balanced, medium-strength cup.

How many grams of coffee per cup?

Using the SCA standard of 1:16 and a US cup of 237 ml: 237 / 16 ≈ 14.8 grams of coffee per cup. For two cups (474 ml), you'd use about 29.6 g. Strong drinkers at 1:15 would use about 15.8 g per cup.

How much coffee for 1 liter of water?

For 1 liter (1000 ml) of water: at 1:15 (strong) use 66.7 g, at 1:16 (medium) use 62.5 g, at 1:17 (mild) use 58.8 g. These amounts work for pour-over, drip, and most filter brew methods.

What is a 1:16 coffee ratio?

A 1:16 ratio means 1 gram of coffee to 16 grams (ml) of water. This is considered the medium or 'golden' ratio recommended by the Specialty Coffee Association. For 20 grams of coffee, you would use 320 ml of water, producing about 1.35 cups.

How does brew ratio affect coffee taste?

Lower ratios (less water per gram of coffee) produce stronger, more intense coffee. Higher ratios produce lighter, more delicate cups. Beyond taste, ratio affects extraction: too little water (under-extracted) = sour, weak; too much water (over-extracted) = bitter. The 1:15–1:17 range hits the sweet spot for most filter brews.

What ratio is best for French press?

French press typically uses a 1:12 to 1:15 ratio because full-immersion brewing is less efficient than filter brewing, and coffee grounds remain in contact with water the entire time. A 1:12 to 1:14 ratio prevents the coffee from tasting weak despite the longer steep time.

How many tablespoons of coffee per cup?

A standard coffee scoop or tablespoon holds about 5–7 grams of ground coffee. At 1:16 ratio per 237 ml cup: you need ~14.8 g, which is approximately 2–3 tablespoons. This varies by grind size and density, so weighing coffee with a scale gives the most consistent results.

What is the SCA coffee brewing standard?

The Specialty Coffee Association (SCA) recommends brewing 55 grams of coffee per liter of water (1:18.2 ratio), with a water temperature of 91–96°C (195–205°F), and a total dissolved solids (TDS) in the final cup of 1.15–1.35%. This produces what is considered 'ideal' strength for filter coffee.

The Coffee-to-Water Ratio

The golden ratio for coffee is expressed as 1:X, meaning 1 gram of coffee to X grams (ml) of water. Professional baristas and the Specialty Coffee Association (SCA) recommend a ratio between 1:15 and 1:18 for most brew methods.

Water (ml) = Coffee (g) × Ratio

Example: 20 g coffee × 16 = 320 ml water = 1.35 cups

Brew Ratio Guide

StrengthRatioWater for 20g coffee
Strong1:15300 ml
Medium (SCA standard)1:16320 ml
Mild1:17340 ml
Light1:18360 ml
Espresso1:240 ml
French Press1:12–15240–300 ml

Ratios by Brew Method

Pour Over / Drip: 1:15–1:17. Standard filter coffee. SCA recommends 55 g/liter (≈ 1:18).
French Press: 1:12–1:15. Uses full immersion, so a slightly stronger ratio compensates for fines staying in the cup.
AeroPress: 1:10–1:16 depending on whether you dilute the concentrate.
Espresso: 1:1.5–1:2.5 (ristretto to lungo). Very concentrated; typically 18–20 g of coffee yields 36–40 ml of espresso.
Cold Brew Concentrate: 1:4–1:8 with cold water, steeped 12–24 hours. Dilute 1:1 before drinking.

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