Coffee to Water Ratio Calculator

Coffee-to-water ratio is the single most important variable in brewing great coffee. Too little coffee produces weak, watery results; too much produces bitter, astringent coffee. The specialty coffee industry uses grams of coffee per milliliters of water (or liters) as the standard measure.

Core ratio formula: Coffee (g) = Water (mL) × Brew Ratio

Or: Brew Ratio = Coffee (g) ÷ Water (mL)

Standard brew ratios by method:

• Drip (automatic): 1:15–1:17 (1 g coffee per 15–17 mL water)
• Pour-over (V60, Chemex): 1:15–1:17
• French press: 1:12–1:15 (coarser grind, shorter contact time ratio compensates)
• AeroPress: 1:10–1:14 (concentrated; often diluted after)
• Espresso: 1:2–1:3 (18–21 g coffee → 36–63 g espresso output)
• Cold brew concentrate: 1:4–1:6 (dilute 1:1 with water or milk before drinking)
• Moka pot: determined by pot size, not adjustable (fills basket fully)

Volume to weight conversion: Water: 1 mL = 1 g (precise at room temperature) So 300 mL water = 300 g water.

Cups to milliliters:

• 1 US cup = 237 mL (standard)
• 1 coffee “cup” on most machines = 150 mL (note: not the same as a US cup)
• 1 mug ≈ 350–400 mL

Golden Ratio (Specialty Coffee Association standard): 55 g of coffee per 1 liter of water (1:18.2 ratio) This is the SCA’s recommended baseline for drip coffee — adjust by ±5 g to personal taste.

Worked example: You want to brew 600 mL of pour-over coffee using a 1:16 ratio.

Coffee needed = 600 mL ÷ 16 = 37.5 g (round to 38 g)

Grind: medium-fine (table salt texture for V60) Water temperature: 91–96°C (196–205°F) Total brew time: 3.5–4 minutes

For espresso: 18 g of coffee in, target 36 g espresso out (1:2 ratio), in 25–30 seconds extraction.

Strength vs extraction: Ratio controls strength (concentration). Grind size and water temperature control extraction (which flavor compounds are dissolved). Fixing ratio first, then adjusting grind, is the correct order for dialing in a recipe.