Quick answer
The brew ratio is 1 : (water ÷ coffee). 20 g of coffee with 320 g of water is 1:16, which is 62.5 g of coffee per litre.
Enter the coffee and water weights. The calculator returns the ratio and the grams of coffee per litre.
Related tools: Tea Ratio Calculator: Tea leaf per amount of water. Coffee Extraction Yield Calculator: Extraction yield from dose, beverage weight and TDS. Rice to Water Ratio Calculator: Water needed for rice at the ratio you prefer.
How to use the Coffee Brew Ratio Calculator
- Enter coffee (g) (above 0).
- Enter water (g) (above 0).
- Press Calculate to see the result, and use Reset to start again.
| Input | What to enter | Allowed values |
|---|---|---|
| Coffee | A number, in g | > 0 |
| Water | A number, in g | > 0 |
Formula and method
Formula
ratio = 1 : (water ÷ coffee)
IEEE-754 double precision; shown to the decimals indicated.
Water in grams (1 mL of water ≈ 1 g).
Worked examples
These examples are verified: each one is an automated test case that the live calculator must reproduce exactly.
Example 1
Inputs: Coffee = 20; Water = 320.
| Result | Value |
|---|---|
| Brew ratio | 1:16 |
| Grams of coffee per liter | 62.5 |
Example 2
Inputs: Coffee = 30; Water = 500.
| Result | Value |
|---|---|
| Brew ratio | 1:16.67 |
| Grams of coffee per liter | 60 |
Example 3
Inputs: Coffee = 15; Water = 255.
| Result | Value |
|---|---|
| Brew ratio | 1:17 |
| Grams of coffee per liter | 58.82 |
The first line is the headline result (brew ratio). Below it the coffee Brew Ratio Calculator lists grams of coffee per liter, which describe the same case from other angles. IEEE-754 double precision; shown to the decimals indicated.
Typical ratios
Filter coffee is commonly 1:15 to 1:17 (about 60 to 67 g/L), espresso about 1:2, and cold brew concentrates 1:4 to 1:8. The SCA golden cup guideline is about 55 g/L, or 1:18.
Adjusting by taste
Taste decides the right ratio. If the cup is weak, use more coffee or less water; if bitter, adjust grind or brew time rather than ratio. Weighing both coffee and water gives repeatable results.
How the result changes with coffee
Holding every other input at the first worked example, this table changes only coffee. It shows how sensitive the answer is to that one value; each row was produced by running this calculator.
| Coffee | Brew ratio | Grams of coffee per liter |
|---|---|---|
| 10 | 1:32 | 31.25 |
| 20 | 1:16 | 62.5 |
| 40 | 1:8 | 125 |
| 80 | 1:4 | 250 |
What happens with invalid input
These messages are produced by the calculator itself, so you know what to fix.
- Coffee: entering "0" shows "Coffee must be greater than 0." beside that field and no result.
- Water: entering "0" shows "Water must be greater than 0." beside that field and no result.
Choosing between the Coffee Brew Ratio Calculator and similar calculators
Each row shows what a related calculator on this site asks for and what it returns, so you can pick the one that matches your question.
| Calculator | You enter | It returns |
|---|---|---|
| [Tea Ratio Calculator](/cooking/tea-steeping-ratio-calculator/) | tea leaf and water | Ratio |
| [Coffee Extraction Yield Calculator](/cooking/coffee-extraction-ratio-calculator/) | coffee dose, beverage weight and tDS | Extraction yield |
| [Rice to Water Ratio Calculator](/cooking/rice-water-ratio-calculator/) | rice and water per 1 part rice | Water needed |
| [Ratio Calculator](/math/ratio-calculator/) | first number and second number | Simplified ratio |
| [K/D Ratio Calculator](/other/kd/) | kills and deaths | K/D ratio |
Background: cooking measurements
For baking, weight is more reliable than volume. A cup holds a fixed volume but its weight depends on the ingredient's density, and a cup of flour can vary by 20 to 30 grams depending on how it is scooped, so published gram-per-cup values for the same ingredient differ from site to site. Spoon and level flour if you must measure by volume.
Check which cup a recipe uses: the US cup is 236.588 mL, while a metric cup is 250 mL.
Assumptions and limitations
- Taste decides the right ratio
Cooking times are guides. Use a food thermometer to confirm safe internal temperatures.
If a required value is empty, not a number, or outside its allowed range, the form marks that field with a message and shows no result instead of a misleading number. The automated checks deliberately try invalid entries for coffee and water to confirm this.
Frequently asked questions
What ratio for a pour-over?
Around 1:16 is a common starting point.
How much coffee for 500 g of water?
At 1:16, 500 g of water needs 500 ÷ 16 = 31.25 g of coffee.
Is the ratio by weight?
Yes. The ratio compares grams of water to grams of coffee; cups and scoops vary with grind and roast.
What does the Coffee Brew Ratio Calculator calculate?
Coffee-to-water ratio and grams per liter. It returns Brew ratio and Grams of coffee per liter.
What formula does the Coffee Brew Ratio Calculator use?
ratio = 1 : (water ÷ coffee). Water in grams (1 mL of water ≈ 1 g).
What do I need to enter in the coffee Brew Ratio Calculator?
You enter Coffee (g) and Water (g).
How is the result rounded or limited?
IEEE-754 double precision; shown to the decimals indicated. Taste decides the right ratio.
What is an example of a coffee Brew Ratio result?
With coffee 20 and water 320, the brew ratio is 1:16.
Where does the method come from?
The method follows: Specialty Coffee Association brew ratio convention.
Can I rely on this calculator for a decision?
Cooking times are guides. Use a food thermometer to confirm safe internal temperatures. For this calculator in particular: Taste decides the right ratio.
Related calculators
- Tea Ratio Calculator — Tea leaf per amount of water.
- Coffee Extraction Yield Calculator — Extraction yield from dose, beverage weight and TDS.
- Rice to Water Ratio Calculator — Water needed for rice at the ratio you prefer.
- Ratio Calculator — Simplify a ratio of two whole numbers.
- K/D Ratio Calculator — Kill/death ratio.
- Debt Ratio Calculator — Total liabilities as a share of total assets.
Sources
- Specialty Coffee Association brew ratio convention
Content last reviewed 2026-11-04. Formulas and worked examples are checked by automated tests against independently computed values.