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Brewing basics
Coffee-to-water ratio explained
What 1:16 means, the right ratio for each brew method, and how to convert scoops and cups to grams.
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Short answer
Start at 1:16 for filter coffee: 1 gram of coffee for every 16 grams (ml) of water, so 20 g of coffee to 320 g of water. Go to 1:15 for stronger or 1:17 for lighter. French press often uses 1:12–1:15, and espresso uses about 1:2.
A brew ratio is simply the weight of coffee compared to the weight of water. "1:16" means one part coffee to sixteen parts water. It's the single most useful number in home brewing, because it controls how strong your coffee is, and it lets you repeat a cup you liked. Since 1 ml of water weighs 1 g, you can measure water by weight on a scale or by volume in a measuring jug.
Why ratio matters
Two different things determine how coffee tastes:
- Strength: how concentrated the coffee is. The ratio mostly controls this.
- Extraction: how much flavor the water pulled out of the grounds. Grind size, time and temperature mostly control this.
If your coffee tastes balanced but watery or too intense, change the ratio. If it tastes sour or bitter, change the grind first. Our dialing-in guide explains how. Mixing up the two is the most common reason people chase their tails.
The "golden ratio"
The Specialty Coffee Association's long-standing Golden Cup guideline is 55 g of coffee per liter of water, give or take 10%. That works out to roughly 1:18, or about 1:16.5 to 1:20 across the allowed range. Many specialty cafés and home brewers now prefer slightly stronger, around 1:15 to 1:17. There's no single correct number. Start at 1:16 and adjust to taste.
Ratios by brew method
| Method | Typical ratio | Example dose | Notes |
|---|---|---|---|
| Pour-over (V60, Kalita) | 1:15–1:17 | 15 g : 250 g | Start at 1:16 |
| Chemex | 1:15–1:17 | 40 g : 640 g | Thick filter; grind a little coarser |
| Drip machine | 1:15–1:18 | 60 g : 1,000 g | Check the machine's max capacity |
| French press | 1:12–1:15 | 30 g : 450 g | Stronger ratios suit the heavy body |
| AeroPress | 1:11–1:16 | 15 g : 220 g | Can also brew a concentrate and dilute |
| Cold brew concentrate | 1:5–1:8 | 100 g : 700 g | Dilute about 1:1 with water or milk |
| Espresso | 1:2 (1:1.5–1:3) | 18 g in : 36 g out | Here the ratio is measured as liquid out, not water in |
Rather than doing the arithmetic, use our brew ratio calculator. Pick a method and a dose, and it gives you the water amount, temperature, grind and pour schedule.
Doing the math
The formula is short:
- Water = coffee × ratio. 20 g × 16 = 320 g.
- Coffee = water ÷ ratio. 500 g ÷ 16 ≈ 31 g.
Keep in mind that the grounds hold on to some water, roughly two to three times their own weight depending on the brewer. So 320 g of water poured over 20 g of coffee yields about 260–280 g in the cup. If you want a specific amount in your mug, pour a bit extra.
What if you don't have a scale?
You can get close with spoons and a measuring cup, but expect some variation. Beans differ in density, and a "tablespoon" can be level or heaped.
- One level tablespoon of ground coffee weighs roughly 5–6 g, depending on roast and grind.
- For a 1:16 mug of about 300 ml of water, use about 19 g, or about 3½ level tablespoons.
- The old "two tablespoons per 6 oz cup" advice works out to roughly 1:15 to 1:18, depending on how full the tablespoons are. That's a reasonable starting point.
A 0.1 g scale costs as little as $20 and removes the guesswork. It's the best-value tool in coffee. See our $150 starter kit.
Beware of "cups"
Coffee makers use a "cup" that's smaller than a normal mug, usually 5 or 6 oz (about 150–180 ml), depending on the brand. Chemex, for example, counts a cup as 5 oz. A "12-cup" machine therefore makes roughly 60–72 oz, not twelve full mugs. When a recipe or a machine mentions cups, check what it actually means, or measure water in grams.
Common questions
Does the ratio change for light and dark roasts?
Slightly. Dark roasts extract more easily and taste stronger, so many people prefer them a touch lighter, around 1:16–1:17. Light roasts are denser and can taste thin at the same ratio, so 1:15–1:16 often suits them better, along with hotter water.
Should I adjust the ratio for iced coffee?
Yes. For pour-over brewed directly over ice (sometimes called Japanese-style iced coffee), replace about a third to 40% of the hot water with ice in the carafe. For example, use 20 g of coffee, 200 g of hot water and 120 g of ice. The total still equals a 1:16 ratio, but the coffee is brewed stronger so the melting ice dilutes it to normal strength.
Why does my coffee taste different with the same ratio?
The ratio fixes strength, but a new bag of beans, a different grind setting or stale coffee changes extraction. When you open a new bag, keep your ratio and re-check the grind.
Adjusting to taste
- Brew at 1:16 with a grind that gives the right brew time for your method.
- If it's balanced but too weak, try 1:15. If it's too strong, try 1:17.
- If it's sour or bitter instead, leave the ratio alone and adjust the grind.
- Once you find your ratio, keep it and change the dose to make more or less coffee.
That last point is the real power of ratios: a recipe you love for one mug scales perfectly to a carafe for four.