The “golden ratio” is 1 gram of coffee to 16–18 grams of water for filter brewing — the SCA’s recommended range, and a reasonable place to start.
The numbers
Filter — 1:16 to 1:18. 60 g of coffee per litre is the same thing expressed differently. French press — 1:15 to 1:17, slightly stronger to compensate for the sediment. AeroPress — 1:12 to 1:16, wide by design. Espresso — 1:2, meaning 18 g in, 36 g out. Moka pot — around 1:7 to 1:10, a concentrate. Cold brew — 1:8 for concentrate, 1:15 to drink as is.
What the ratio controls
Strength — how much dissolved coffee is in the water. It does not directly control extraction.
Extraction is what proportion of the coffee dissolved, and that is governed by grind, temperature and time.
Why it is only a start
Different coffees want different ratios. A dense light roast has more to give and often wants 1:17 or wider. A dark roast at 1:17 can taste thin, and 1:15 suits it better.
Your taste matters more than the number.
Adjusting it
Change one thing. If your brew is weak but tastes correctly extracted — sweet, balanced, no sourness or bitterness — tighten the ratio to 1:15. If it is strong and harsh, extraction is the problem, not the ratio.
Weigh everything. Ratios mean nothing measured by scoop.
Last reviewed 8 August 2026