Coffee to Water Ratio Calculator
The Science of the Perfect Coffee to Water Ratio
Finding the perfect balance between coffee grounds and water is the single most important step in moving from a "decent" cup of joe to a barista-quality brew. Whether you are using a Pour Over, French Press, or AeroPress, the ratio determines the strength, body, and flavor clarity of your beverage.
What is the "Golden Ratio" for Coffee?
The Specialty Coffee Association (SCA) defines the Golden Ratio as 1:18 (1 gram of coffee for every 18 grams of water). However, most home enthusiasts and specialty cafes prefer a slightly stronger profile, typically ranging between 1:15 and 1:17.
- 1:15 Ratio: Produces a full-bodied, punchy cup. Ideal for French Press or those who add milk.
- 1:16 Ratio: The "sweet spot" for most pour-overs (Hario V60, Chemex). Perfectly balances acidity and sweetness.
- 1:17 Ratio: A lighter, more tea-like consistency. Great for highlighting delicate floral notes in light-roast Ethiopian beans.
How to Use the Coffee Ratio Calculator
To get started, you only need to know how much coffee you have or how much water your mug holds. Using a digital scale is highly recommended because measuring by volume (spoons) is notoriously inaccurate due to variations in roast density.
Example Calculation:
If you have 20 grams of coffee and want a standard 1:16 brew:
20g Coffee x 16 = 320g (ml) Water.
Note: Our calculator also accounts for water absorption. Coffee grounds usually absorb about twice their weight in water. So, if you use 320ml of water with 20g of coffee, your actual drinkable yield will be approximately 280ml.
Tips for a Better Brew
1. Use a Scale
A tablespoon of dark roast weighs significantly less than a tablespoon of light roast because dark roast beans are more porous and puffed up. Weighing in grams ensures consistency every single morning.
2. Water Quality
Coffee is 98% water. If your tap water tastes like chlorine, your coffee will too. Use filtered water for the best results.
3. Adjust for Method
If your coffee tastes too bitter, try a coarser grind or a slightly higher ratio (e.g., move from 1:15 to 1:16). If it tastes sour or weak, try a finer grind or a lower ratio (e.g., move from 1:17 to 1:15).
Frequently Asked Questions
How many grams is a tablespoon of coffee?
On average, a level tablespoon of whole bean coffee is about 4-7 grams, but this varies wildly. It is always better to weigh!
Does the ratio change for iced coffee?
Yes. For "Flash Brew" or Japanese Iced Coffee, you typically use a 1:10 ratio with hot water and brew directly over a calculated mass of ice to reach a final 1:16 dilution.