*Yield is estimated based on coffee ground absorption (approx. 2g of water per 1g of coffee).
Understanding Coffee Ratios
The coffee-to-water ratio is the single most important variable in brewing consistent, delicious coffee. It refers to the weight of dry coffee grounds relative to the weight of the water used to brew it. Most specialty coffee shops use a ratio between 1:15 and 1:18 for pour-overs and drip coffee.
Common Ratio Guidelines
Ratio
Intensity
Best For
1:2
Very Intense
Espresso
1:10
Concentrated
Cold Brew (Dilutable)
1:15
Strong
French Press / Aeropress
1:16
Balanced
V60 / Chemex / Drip
1:17
Light & Sweet
Standard Filter Coffee
The "Golden Cup" Standard
The Specialty Coffee Association (SCA) defines the Golden Cup Standard as a ratio of 55 grams of coffee per liter of water (approximately 1:18). However, flavor is subjective. If your coffee tastes too bitter or strong, try a higher ratio (like 1:17). If it tastes sour or watery, try a lower ratio (like 1:15).
Example Calculation
If you want to brew a standard 12oz mug of coffee (roughly 355ml), and you prefer a 1:16 ratio:
Step 1: 355ml water / 16 (ratio) = 22.2 grams of coffee.
Step 2: Weigh out 22.2g of beans and grind them.
Step 3: Brew with exactly 355g of water (since 1ml water = 1g).
function updateFields() {
var mode = document.getElementById("calcMode").value;
var label = document.getElementById("mainInputLabel");
var input = document.getElementById("mainInput");
if (mode === "coffee") {
label.innerHTML = "Amount of Coffee (g)";
input.placeholder = "e.g. 20";
} else {
label.innerHTML = "Amount of Water (ml/g)";
input.placeholder = "e.g. 320";
}
}
function applyPreset() {
var preset = document.getElementById("presetRatios").value;
if (preset !== "") {
document.getElementById("ratioInput").value = preset;
}
}
function calculateBrew() {
var mode = document.getElementById("calcMode").value;
var ratio = parseFloat(document.getElementById("ratioInput").value);
var inputVal = parseFloat(document.getElementById("mainInput").value);
var coffeeResult = 0;
var waterResult = 0;
var yieldResult = 0;
if (isNaN(ratio) || isNaN(inputVal) || ratio <= 0 || inputVal <= 0) {
alert("Please enter valid positive numbers.");
return;
}
if (mode === "coffee") {
coffeeResult = inputVal;
waterResult = inputVal * ratio;
} else {
waterResult = inputVal;
coffeeResult = inputVal / ratio;
}
// Absorption rule: coffee grounds retain approx twice their weight in water
yieldResult = waterResult – (coffeeResult * 2);
if (yieldResult < 0) yieldResult = 0;
document.getElementById("resCoffee").innerHTML = coffeeResult.toFixed(1) + " g";
document.getElementById("resWater").innerHTML = waterResult.toFixed(0) + " ml (g)";
document.getElementById("resYield").innerHTML = yieldResult.toFixed(0) + " ml approx.";
document.getElementById("results").style.display = "block";
}