The Ideal Coffee-to-Water Ratio for Drip Coffee

The coffee-to-water ratio determines how much water is used relative to the amount of ground coffee. For drip coffee, a ratio between about 1:15 and 1:18 is a useful starting range, with 1:16 to 1:17 providing a practical middle ground.

There is no single ideal ratio for every coffee. The right starting point depends on the desired beverage strength, coffee, grind size, brewing method and personal taste.

What does coffee-to-water ratio mean?

Coffee-to-water ratio describes the amount of water used relative to the mass of ground coffee. A 1:16 ratio means 1 g of coffee for every 16 g of water.

For drip coffee, the ratio can also be expressed as grams of coffee per litre of water. 60 g of coffee per litre of water corresponds to approximately a 1:16.7 ratio.

What is the ideal coffee-to-water ratio for drip coffee?

A ratio between 1:15 and 1:18 is a useful starting range. If you do not have an established recipe, start around 1:16 or 1:17 and adjust the ratio according to taste.

When testing home brewers, the SCA starts with 55 g of coffee per litre of water and then considers grind size and contact time when evaluating the brew.

What is the difference between 1:15, 1:16, 1:17 and 1:18?

With the same amount of water, a lower ratio number means more coffee is used. This increases the concentration of the finished beverage. A higher ratio number uses more water per gram of coffee.

Is 1:16 a good ratio for drip coffee?

Yes, 1:16 is a practical starting point because it is easy to calculate and reproduce. It is not, however, a universally ideal ratio.

With 20 g of coffee, a 1:16 ratio requires 320 g of water. With 25 g of coffee, it requires 400 g of water.

Is 1:17 a good ratio for drip coffee?

1:17 is also a useful starting point and uses slightly more water per gram of coffee than 1:16. As a recipe ratio, this produces a lower concentration when the coffee dose remains constant.

With 20 g of coffee, a 1:17 ratio requires 340 g of water.

How much coffee do you need at a 1:16 ratio?

At 1:16, divide the amount of water by 16 to calculate the coffee dose. For 320 g of water, for example, you need 20 g of coffee.

How do you calculate the coffee-to-water ratio?

Divide the amount of water by the amount of coffee to calculate the ratio number.

Ratio number = water amount ÷ coffee amount

For example, 400 g of water divided by 25 g of coffee equals 16. The recipe therefore has a 1:16 ratio.

How do you calculate the coffee dose from the ratio?

Divide the amount of water by the ratio number. With 500 g of water at 1:17, for example, 500 ÷ 17 gives approximately 29.4 g of coffee.

Coffee dose = water amount ÷ ratio number

How do you calculate the amount of water from the ratio?

Multiply the coffee dose by the ratio number. With 25 g of coffee at 1:16, the calculation is 25 × 16 = 400 g of water.

Water amount = coffee dose × ratio number

How does the ratio affect coffee flavour?

The ratio primarily affects the concentration of the finished beverage. More coffee with the same amount of water increases concentration, while more water with the same coffee dose decreases concentration.

The ratio should not, however, be treated as the same thing as extraction. Grind size, water temperature, contact time and flow also influence how much soluble material is extracted from the coffee grounds.

What is the difference between brew ratio and extraction?

Brew ratio describes the relationship between brewing water and ground coffee. Extraction describes the proportion of soluble material that moves from the coffee grounds into the brewed beverage.

A ratio alone therefore cannot predict exactly how a coffee will taste. Two recipes with the same ratio can produce different results when grind size or brewing time changes.

What role does beverage strength play?

Beverage strength describes how concentrated the finished coffee is. It is closely related to the amount of coffee and water used, but it is also affected by extraction.

The SCA treats brew ratio, TDS and extraction yield as related brewing measurements. Ratio is therefore an important recipe variable, but it is not the only one.

Should you start with 1:15 or 1:18?

If you do not already have a recipe, a middle starting point such as 1:16 or 1:17 is easier to evaluate. You can then move gradually toward 1:15 or 1:18.

Changing the ratio in small steps makes it easier to identify whether you prefer a higher or lower beverage concentration.

How does grind size affect the ideal ratio?

Grind size affects water flow and extraction conditions. As a result, a ratio that works well at one grind setting may produce a different result at another.

When dialing in a recipe, avoid making large changes to both ratio and grind size at the same time.

For more detail, see our guide to the right grind size for drip coffee.

How does the amount of water affect the ratio?

Water is one of the two direct variables in the ratio. Increasing the water while keeping the coffee dose constant increases the ratio number and produces a lower recipe concentration.

Increasing the coffee dose while keeping the water constant lowers the ratio number and produces a higher recipe concentration.

What coffee-to-water ratio does the SCA use?

When testing home brewers, the SCA starts with 55 g of coffee per litre of water. The ratio is then adjusted according to grind size and contact time to achieve defined beverage-strength and extraction ranges.

Mathematically, 55 g of coffee per litre corresponds to approximately a 1:18.2 ratio.

Can the ideal ratio be the same for every coffee?

No. Ratio is a recipe parameter rather than a universal flavour rule.

Coffees differ in roast level, processing, density and sensory profile. A ratio that works well for one coffee may therefore need to be adjusted for another.

How should you change the ratio when dialing in a recipe?

Change the ratio in small steps while keeping other important parameters as consistent as possible. This makes the effect of the change easier to evaluate.

If the coffee simply tastes too concentrated or too light, the ratio can be a useful adjustment. If it tastes sour, bitter or otherwise unbalanced, also check grind size, temperature and brew time.

How do you scale a coffee-to-water ratio?

To scale a recipe, keep the ratio constant and increase or decrease the coffee and water together.

What is the most important thing about coffee-to-water ratio?

The most important thing is to use the ratio as a repeatable starting point rather than as a rigid rule. Weigh both coffee and water, begin with a clear ratio and change one parameter at a time when dialing in the recipe.

For the broader topic, see our complete guide to drip coffee ratios and quantities. For a practical dose calculation, see our guide to how much coffee to use for drip coffee.