Coffee Ratio Calculator - Brew the Perfect Cup

How to use this tool

1. Select your brew method.
2. For filter methods, enter water in milliliters or US fluid ounces; for espresso, enter the coffee dose in grams and choose a dose-to-yield ratio.
3. Read the recommended filter coffee dose in grams and tablespoons, or the estimated espresso yield in grams and approximate milliliters.

The golden ratio

The Specialty Coffee Association (SCA) recommends a brew ratio of 1:15 to 1:18 (coffee:water by weight). The most common starting point is 1:16 - 1g of coffee for every 16g (ml) of water.

Brew method ratios

Filter brew ratios compare dry coffee with water by weight; 1:16 means 1 gram of coffee for 16 grams of water. Espresso uses a separate dose-to-yield convention, comparing coffee grounds in with brewed espresso out. These are starting ranges, so adjust to the coffee and taste you prefer.

For pour-over, French press, drip, cold brew, AeroPress, and Moka pot, the calculator uses the same ratio ranges shown here. Espresso starts at 1:2 by weight; enter a dose and select a ristretto-to-lungo yield ratio to estimate the beverage output. Milliliters and US fluid ounces describe the water volume for filter methods, while espresso yield milliliters are only an approximation because crema and beverage density vary.

Extraction and taste

Under-extracted (too little time or water): sour, salty, hollow flavor. Over-extracted (too much time or fine grind): bitter, harsh, dry finish. Adjust your grind size first; adjust your ratio second.

Water quality matters

Water is 98–99% of your brewed coffee, so its mineral content directly affects extraction. The Specialty Coffee Association recommends water with a Total Dissolved Solids (TDS) of approximately 150 ppm and hardness between 50–175 ppm. Very hard water (high magnesium and calcium) causes over-extraction and bitter flavors; very soft water (near-zero TDS, such as distilled water) under-extracts and tastes flat. Filtered tap water is usually the easiest starting point.

Bloom / pre-infusion

Fresh coffee releases CO₂ gas (off-gassing) that was absorbed during roasting. When you first add hot water to ground coffee, this CO₂ escapes rapidly, creating a bloom or "crust". If you don't allow the gas to escape first, it can interfere with even water distribution and extraction. The standard bloom technique is to add twice the weight of water as coffee (e.g., 30 g water for 15 g grounds) and wait 30–45 seconds before pouring the rest. This is especially important for pour-over methods. Coffee roasted within the past 1–2 weeks blooms most vigorously.

Freshness guide

• Buy within the roast date: look for a roast date on the bag (not a "best by" date). Aim to buy coffee roasted within the last 4 weeks and consume it within 2–4 weeks of the roast date for optimal flavor.
• Grind immediately before brewing: pre-ground coffee goes stale within hours of grinding due to the massive increase in surface area exposed to oxygen. A burr grinder produces more consistent particle sizes than a blade grinder and is strongly preferred for pour-over and espresso.
• Storage: store beans in an airtight, opaque container at room temperature. Refrigerating coffee is generally not recommended (moisture and odor absorption). Freezing works for long-term storage of unopened, vacuum-sealed bags only.