Coffee to Water Ratio: The Simple Math for Perfect Coffee

Great coffee at home is mostly a question of proportion. The coffee to water ratio tells you how many grams of water you use for each gram of ground coffee: at 1:16, you brew 15 g of coffee with 240 g (240 mL) of water. For drip and pour-over, a ratio between 1:15 and 1:18 is a reliable starting point, and the Specialty Coffee Association’s Golden Cup standard, 55 grams of coffee per liter of water, works out to about 1:18.

Once you know the ratio, every recipe becomes simple division. Here are the formulas, the ratios for each brewing method, a chart for 1 to 8 cups and a quick way to adjust the strength to your taste.

Key takeaways

  • A ratio is water divided by coffee, by weight. 1:16 means 1 g of coffee for every 16 g of water.
  • Golden Cup: the SCA recommends 55 g of coffee per liter of water, plus or minus 10%, which is roughly 1:16.5 to 1:20.
  • Each method has its own range: about 1:13–1:16 for pour-over, 1:10–1:16 for French press, 1:2 for espresso and 1:4–1:5 for cold brew concentrate, according to the National Coffee Association (NCA).
  • Weigh if you can. One milliliter of water weighs about one gram, but a tablespoon of ground coffee can vary in weight.
  • Adjust in small steps. Going from 1:16 to 1:15 means about 7% more coffee, enough to taste the difference.

In this article

  1. What the ratio means
  2. Three formulas you need
  3. The Golden Cup and the Golden Ratio
  4. Ratios by brewing method
  5. Chart: how much coffee for 1 to 8 cups
  6. Grams vs tablespoons
  7. How to adjust the ratio to your taste
  8. Beans to practice with
  9. FAQ
  10. Sources

What the ratio means

A brewing ratio compares two weights: the dry ground coffee and the water you brew it with. Written as 1:16, it reads “one part coffee to sixteen parts water.” The bigger the second number, the more water per gram of coffee and the lighter the cup.

Weights work better than volumes for two reasons. First, water is easy: one milliliter weighs about one gram, so 240 mL of water is about 240 g, and a kitchen scale or a measuring jug both work. Second, coffee is not: how much ground coffee fits in a spoon depends on the grind, the roast and how you scoop. A scale removes that guesswork.

Two details are worth knowing before you start:

  • The ratio counts the water you pour, not the coffee you drink. Wet grounds hold on to some water, so your cup will be a little smaller than the water you used.
  • Espresso is the exception. Its ratio compares the dry dose with the liquid espresso in the cup (the yield). A 1:2 espresso means 18 g of coffee in, 36 g of espresso out.

Three formulas you need

Every coffee recipe can be solved with one of these:

  • Coffee (g) = Water (g) ÷ Ratio
  • Water (g) = Coffee (g) × Ratio
  • Ratio = Water (g) ÷ Coffee (g)

Worked example 1: a 12 oz travel mug

12 US fl oz is about 355 mL, so about 355 g of water. At 1:16: 355 ÷ 16 = 22.2, so use about 22 g of coffee.

Worked example 2: you only have 20 g of beans left

At 1:16: 20 × 16 = 320 g of water. Brew 320 mL and you keep the same strength with less coffee.

Worked example 3: checking a recipe you found

A recipe calls for 30 g of coffee and 500 g of water. 500 ÷ 30 = 16.7, so it is a 1:16.7 recipe, right in the normal range for filter coffee.

Converting ratios to grams per liter

Divide 1,000 by the ratio: 1:15 is 66.7 g per liter, 1:16 is 62.5 g, 1:17 is 58.8 g and 1:18 is 55.6 g. Working backward, the SCA’s 55 g per liter is 1,000 ÷ 55 = 18.2, or about 1:18.

The Golden Cup and the Golden Ratio

You will see two “golden” guidelines, one in grams and one in spoons.

SCA Golden Cup: 55 g per liter

The Specialty Coffee Association’s brewing best practices recommend a coffee-to-water ratio of 55 g/L ± 10% to reach its Golden Cup Standard, with water at 93 °C ± 3 °C (200 °F ± 5 °F) when it meets the coffee. Plus or minus 10% means 49.5 to 60.5 g per liter, or about 1:16.5 to 1:20. The same guidance matches grind to contact time: about 1–4 minutes for a fine grind, 4–6 minutes for drip and 6–8 minutes for a coarse grind.

NCA Golden Ratio: 1 to 2 tablespoons per 6 oz

The National Coffee Association’s drip guide calls 1 to 2 tablespoons of ground coffee for every 6 fl oz of water the “Golden Ratio.” Converting it to weight shows how wide that range is. Six fluid ounces is about 177 mL. If a level tablespoon holds about 5 g of ground coffee (a working assumption; see the tablespoon section below), then:

  • 2 tablespoons = about 10 g, and 177 ÷ 10 = 1:17.7, very close to the SCA Golden Cup.
  • 1 tablespoon = about 5 g, and 177 ÷ 5 = 1:35, a much lighter cup.

In other words, the top of the NCA range lines up with the SCA standard. If your coffee tastes thin, use the full 2 tablespoons.

Ratios by brewing method

Immersion methods, espresso and cold brew all work differently, so their ratios differ too. These ranges come from the SCA and the NCA’s brewing guides:

Method Ratio (coffee : water) Example Grind Contact time
Drip coffee maker About 1:16.5–1:20 (SCA Golden Cup, 55 g/L ± 10%) 55 g coffee + 1 L water Medium About 5 minutes
Pour-over 1:13–1:16 15 g coffee + 240 g water (1:16) Medium 2–4 minutes
French press 1:10–1:16 33 g coffee + 500 g water (1:15) Coarse About 4 minutes
Espresso 1:2 (coffee : espresso in the cup) 18 g coffee, 36 g espresso Fine 20–30 seconds
Cold brew concentrate 1:4–1:5 200 g coffee + 1 kg water (1:5) Coarse About 12 hours

A few notes on reading the table:

  • French press has the widest range. A good starting point is 1:15; go toward 1:12 if you like a heavier cup.
  • Espresso is measured in the cup. For the full technique, read our guide to making espresso at home.
  • Cold brew concentrate is strong on purpose and meant to be diluted with water, milk or ice. Our Cold Brew Coffee instructions use a milder mix, about 1 cup (85 g) of coarse grounds per liter of water, which is roughly 1:12.

Chart: how much coffee for 1 to 8 cups

This chart uses a cup of 240 mL (about 8 fl oz) of water, the cup size used on US nutrition labels. Each value is simply the water divided by the ratio, rounded to the nearest gram. The last column converts the 1:16 column to level tablespoons at 5 g each.

Cups Water 1:15 (strong) 1:16 1:17 1:18 (light) Tablespoons at 1:16
1 240 mL (8 fl oz) 16 g 15 g 14 g 13 g 3
2 480 mL (16 fl oz) 32 g 30 g 28 g 27 g 6
3 720 mL (24 fl oz) 48 g 45 g 42 g 40 g 9
4 960 mL (32 fl oz) 64 g 60 g 56 g 53 g 12
5 1,200 mL (41 fl oz) 80 g 75 g 71 g 67 g 15
6 1,440 mL (49 fl oz) 96 g 90 g 85 g 80 g 18
7 1,680 mL (57 fl oz) 112 g 105 g 99 g 93 g 21
8 1,920 mL (65 fl oz) 128 g 120 g 113 g 107 g 24

Watch out for coffee maker “cups”

The cup markings on a coffee maker are usually smaller than a measuring cup: on many US machines, one marked “cup” is about 5 fl oz (148 mL) of water, but brands differ, so check your manual. The difference adds up fast. Four 240 mL mugs need 960 mL of water and 60 g of coffee at 1:16. Four 5 oz machine “cups” need only about 591 mL of water, so 591 ÷ 16 = 37 g of coffee. Using the mug recipe in the machine-cup amount of water would make the coffee much stronger than you intended.

Grams vs tablespoons

A US tablespoon is a unit of volume: for nutrition labeling, US regulations define it as 15 mL. How many grams of ground coffee fit in those 15 mL depends on the grind, the roast and whether the spoon is level or heaped, so there is no single correct conversion.

That is why the tables above treat 5 g per level tablespoon as an assumption, not a fact. As a reference point, our own cold brew instructions measure about 1 cup (85 g) of coarse grounds; a cup holds 16 tablespoons, so that is about 5.3 g per tablespoon for that grind.

Calibrate your own spoon in one minute

  1. Put a small bowl on a kitchen scale and set it to zero.
  2. Add 5 level tablespoons of the coffee you normally use.
  3. Divide the weight by 5. That is your personal grams per tablespoon.
  4. Use it to convert any gram recipe: grams needed ÷ grams per tablespoon = tablespoons.

For example, if 5 tablespoons weigh 27 g, your spoon holds 5.4 g. A 22 g mug then needs 22 ÷ 5.4 = about 4 tablespoons. If your coffee scoop came with a machine, measure it the same way, since scoop sizes vary.

How to adjust the ratio to your taste

The ratio controls strength: how concentrated your cup tastes. Grind size, water temperature and brew time mostly control extraction: how much flavor you pull out of the grounds. Use the ratio to fix strength and the grind to fix balance.

Your cup tastes… Likely cause What to change
Weak and watery, but not sour Too much water for the coffee Move one step stronger, for example 1:17 to 1:16
Heavy and intense, but not bitter Too much coffee for your taste Move one step lighter, or add a splash of hot water after brewing
Sour, thin, salty Under-extraction Grind finer or brew a little longer; keep the ratio
Bitter, dry, harsh Over-extraction Grind coarser or shorten the brew; keep the ratio

How big is one step?

Small changes in the ratio are bigger than they look. For the same amount of water, going from 1:16 to 1:15 uses 16 ÷ 15 = 1.067, or about 7% more coffee. Going from 1:16 to 1:17 uses 16 ÷ 17 = 0.941, about 6% less, and 1:16 to 1:18 uses about 11% less. Change one thing at a time, brew the same recipe two or three mornings in a row, then decide.

Write your recipe down

Once you find your favorite, note four numbers: coffee in grams, water in grams, grind setting and brew time. With those, you can repeat a great cup every day, and scale it up or down with the formulas above.

Beans to practice with

A ratio only works if the coffee itself is consistent, which is why fresh, evenly roasted beans make dialing in easier. Our Breakfast Blend is a smooth, nutty medium roast of South American beans and one of our best sellers, a forgiving coffee for testing 1:15 against 1:17 side by side. Explore our best-selling coffees for more options; every bag is roasted 1–5 days before delivery and available whole bean or ground for drip, French press and espresso.

Coffee to water ratio: FAQ

What is the best coffee to water ratio?

For drip and pour-over, start at 1:16 and adjust between about 1:15 and 1:18. The SCA’s Golden Cup standard is 55 g of coffee per liter of water (about 1:18), plus or minus 10%. Espresso and cold brew concentrate use very different ratios, around 1:2 and 1:4–1:5.

How many grams of coffee per cup?

For an 8 fl oz (240 mL) cup, use about 15 g at 1:16, or 13–16 g between 1:18 and 1:15. For a 6 fl oz cup (177 mL), about 10–11 g.

How many tablespoons of coffee per cup?

The NCA suggests 1 to 2 tablespoons per 6 fl oz of water. For a fuller cup in line with the SCA standard, use 2 tablespoons per 6 oz, or about 3 level tablespoons for an 8 oz mug, assuming about 5 g per tablespoon.

Is the ratio by weight or by volume?

By weight. Because 1 mL of water weighs about 1 g, you can still measure the water by volume and only weigh the coffee.

Do I count the water the grounds absorb?

No. Brewing ratios use the water you pour. The grounds keep some of it, so expect a slightly smaller cup than the water you started with.

Sources

  1. Specialty Coffee Association. Protocols and best practices: brewing best practices (Golden Cup Standard). Read
  2. National Coffee Association. How to brew drip coffee (the Golden Ratio). Read
  3. National Coffee Association. How to brew pour-over coffee. Read
  4. National Coffee Association. How to brew French press coffee. Read
  5. National Coffee Association. How to brew espresso. Read
  6. National Coffee Association. How to make cold brew coffee. Read
  7. US Code of Federal Regulations. 21 CFR 101.9, Nutrition labeling of food (household measures: tablespoon and cup). Read
  8. Wikipedia. Cup (unit): coffee cups and coffee maker markings. Read

Facts checked in October 2026.

Keep reading: Whole bean vs ground coffee · How to make espresso at home · Why fresh roasted coffee tastes better · Best sellers

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