In brief
A brew ratio compares the weight of coffee with the weight of water. It is written 1:X. At 1:16, every gram of coffee gets 16 grams of water, so 15 g of coffee takes 240 g of water.
The ratio mostly sets strength. Honest Coffee Guide puts it plainly: more coffee for the water makes a stronger brew, and more water makes a weaker one.
Most filter recipes sit somewhere between about 1:14 and 1:18. Espresso is far more concentrated, usually around 1:2.
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How do you read a brew ratio?
Read the first number as coffee and the second as water, both in grams. A 1:15 ratio with 20 g of coffee means 300 g of water. To find the water, multiply the dose by the second number.
Some people write ratios as grams per liter instead. Perfect Daily Grind gives "50 grams of coffee per liter of water" as a common example. That works out to 1:20.
Weighing matters more than the format. Honest Coffee Guide says to measure coffee by weight, not by volume such as tablespoons. A kitchen scale removes the guesswork.
What brew ratio should you use for each method?
It depends on the method, and no ratio suits every coffee. Honest Coffee Guide publishes these starting points:
| Method | Starting ratio | Range |
|---|---|---|
| Pour-over | 1:15 | 1:14 to 1:16 |
| Chemex | 1:15 | 1:10 to 1:21 |
| French press | 1:15 | 1:12 to 1:18 |
| AeroPress (standard) | 1:15 | 1:12 to 1:18 |
| Moka pot | 1:10 | 1:7 to 1:12 |
| Cold brew | 1:11 | 1:8 to 1:15 |
| Espresso | 1:2 | 2:3 to 2:5 |
Other sources land nearby. Stumptown suggests about 1:17 for pour-over. Counter Culture brews cold brew at 1:8 as a concentrate, then dilutes it. Our coffee-to-water ratio guide goes method by method.
What is the SCA golden ratio?
It is the Specialty Coffee Association's Gold Cup standard for brewed coffee. CoffeeGeek cites it as 55 grams of coffee per liter of water, plus or minus 10 percent. CoffeeGeek works that out to between roughly 1:16 and 1:20.
Whether home brewers should follow it is contested. CoffeeGeek argues the standard was meant for large batch brewing. It found the ratio gave faint, light-bodied cups in small brews like a 250 ml AeroPress, and recommends 1:14 instead.
The idea behind the standard is older. The SCA traces it to Ernest Earl Lockhart's 1957 work for the Coffee Brewing Institute. His brewing control chart plots strength against extraction, with brew ratio linking the two.
Is brew ratio the same as extraction?
No. The ratio sets how strong the cup is. Extraction is how much of the coffee dissolved into the water. A cup can be strong but under-extracted, or weak but well extracted.
Recent research complicates the old picture. The SCA reports UC Davis sensory studies with more than 58,000 data points. They found sweetness falls as both strength and extraction rise, which the classic chart does not show.
Should you change the ratio or the grind?
Usually the grind first. Perfect Daily Grind's fix for sourness or bitterness is the grind size: finer for sour or thin coffee, and coarser for bitter coffee.
Change the ratio when the flavor is balanced but too strong or too weak. That keeps one variable moving at a time, which is the heart of dialing in. The brew calculator scales any ratio to the cup size you want.
If your grinder makes it hard to land on a setting, the ratio cannot rescue the cup. Our post on why your grinder matters more than your brewer explains why.
Sources
- Honest Coffee Guide: Coffee to water ratio calculator
- Perfect Daily Grind: Coffee brew ratios, what you need to know
- CoffeeGeek: One to fourteen, the CoffeeGeek ratio for good coffee brewing
- Specialty Coffee Association: Towards a new brewing chart
- Stumptown Coffee: How to perfect your pour over coffee
- Counter Culture Coffee: Guide to cold brew
By Jeff Gluck · Checked Oct 21, 2026