How the Coffee Ratio Works
Great coffee comes down to one number: the ratio of coffee to water by weight. Express it as 1 part coffee to N parts water, and every batch — a single mug or a full carafe — scales perfectly. Because water weighs almost exactly 1 gram per milliliter, you can treat milliliters of water as grams interchangeably.
Coffee (g) = water (g) ÷ ratio
The Specialty Coffee Association's "golden cup" target sits around 1:18, but most people find 1:16 the sweet spot for filter coffee — bold without being harsh.
Worked Example
You want to brew a 500ml pour-over at a bold 1:16 ratio:
- Coffee needed: 500 ÷ 16 = 31.25 g
- In tablespoons: 31.25 ÷ 5.3 ≈ 5.9 tbsp
- For a milder cup at 1:18: 500 ÷ 18 = 27.8 g
Recommended Ratios by Brew Method
- French press: 1:15 — full body, longer steep, no paper filter.
- Pour-over / drip: 1:16 to 1:17 — clean, balanced, the everyday default.
- SCA golden cup: 1:18 — the specialty standard, bright and nuanced.
- Cold brew concentrate: 1:8 — diluted with water or milk before drinking.
Dial In Your Cup
- Weigh everything. A small scale that reads to 0.1g transforms consistency more than any gadget.
- Use fresh, properly ground beans. Grind just before brewing and match the grind to your method.
- Mind the water temperature. 195–205°F (90–96°C) is the ideal extraction range — just off the boil.
- Adjust one variable at a time. Too weak? Grind finer first. Too bitter? Grind coarser. Then fine-tune the ratio.
Coffee Ratio Calculator FAQ
What is the best coffee-to-water ratio?
The Specialty Coffee Association golden ratio is about 1:18 — one gram of coffee for every 18 grams (ml) of water. Many home brewers prefer a slightly stronger 1:16 or 1:17. A good starting point is 1:16: for a 500ml batch, that means about 31 grams of coffee. Adjust from there to taste, since grind size and brew method also affect strength.
How much coffee do I use for one cup?
For a single 240ml (8 oz) cup at a 1:16 ratio, use about 15 grams of coffee — roughly 3 tablespoons of ground coffee or 2 slightly rounded scoops. For a stronger cup, drop to 1:15 (16g); for a milder cup, go to 1:18 (13g). Weighing is far more reliable than scooping because grind size changes how much fits in a spoon.
Why should I weigh coffee instead of using scoops?
A tablespoon of coffee can range from 4 to 7 grams depending on the grind and how the beans settle, so scooping introduces big swings in strength. A cheap kitchen scale lets you hit the same ratio every time, which is the single biggest upgrade most home brewers can make. Once you find your ideal ratio by weight, your coffee tastes consistent every morning.
Does grind size change the ratio?
The ratio stays the same, but grind size changes how much flavor is extracted from that coffee. Finer grinds extract faster (good for short brews like espresso and pour-over), while coarser grinds extract slower (good for French press and cold brew). If your coffee tastes weak at a normal ratio, grind finer before adding more coffee; if it tastes bitter, grind coarser.
What ratio should I use for French press?
French press works well at a slightly stronger 1:15 because the longer steep and the absence of a paper filter produce a fuller-bodied cup. For a standard 1-liter press, that is about 67 grams of coarsely ground coffee. Steep for around 4 minutes, then press slowly. If it tastes too heavy, move toward 1:16 or 1:17.