I have coffee grounds, how much water?
I want to make a specific volume of coffee
1 :
Standard drip is 1:17. French press is 1:15.
Your Brew Recipe:
*Note: 1ml of water = 1g of water.
Understanding the Coffee to Water Ratio
The secret to a perfect cup of coffee isn't just the quality of the beans—it's the math. The coffee-to-water ratio determines the strength and extraction of your brew. If you use too much water, your coffee will taste thin and over-extracted. If you use too little, it will be sour and overly intense.
The "Golden Ratio"
The Specialty Coffee Association (SCA) suggests a "Golden Ratio" of 1:18, meaning 1 gram of coffee for every 18 grams (or milliliters) of water. However, most coffee enthusiasts prefer a range between 1:15 and 1:17 for a more full-bodied experience.
Brew Method
Suggested Ratio
Resulting Profile
Pour Over / Drip
1:16 – 1:17
Balanced and clean
French Press
1:12 – 1:15
Rich and heavy body
AeroPress
1:11 – 1:13
Concentrated (Dilute later)
Cold Brew (Concentrate)
1:4 – 1:8
Very strong, syrup-like
How to Use This Calculator
To get the most accurate results, we highly recommend using a digital scale to measure both your coffee beans and your water in grams. Volumetric measurements (like tablespoons and cups) are often inaccurate because different coffee roasts have different densities.
Choose your goal: Either start with the amount of coffee you have left in the bag, or the total amount of coffee you want to drink.
Enter the quantity: Input the weight in grams (for coffee) or milliliters (for water).
Select your ratio: Use 15 for a stronger brew or 17 for a lighter, standard specialty coffee profile.
Calculate: The tool will instantly tell you exactly how much of the other ingredient you need.
Pro Tip: Water Absorption
Keep in mind that coffee grounds typically absorb about twice their weight in water. If you use 20g of coffee and 340ml of water (1:17 ratio), you won't actually end up with 340ml of liquid coffee; you'll get roughly 300ml. If you have a specific mug size you need to fill, calculate for a slightly higher water volume to account for this loss.
function updateLabels() {
var mode = document.getElementById('calcMode').value;
var label = document.getElementById('amountLabel');
var input = document.getElementById('inputAmount');
if (mode === 'findWater') {
label.innerText = 'Amount of Coffee Grounds (grams)';
input.placeholder = 'e.g. 20';
} else {
label.innerText = 'Desired Total Water Volume (ml)';
input.placeholder = 'e.g. 340';
}
}
function calculateBrew() {
var mode = document.getElementById('calcMode').value;
var amount = parseFloat(document.getElementById('inputAmount').value);
var ratio = parseFloat(document.getElementById('inputRatio').value);
var resultArea = document.getElementById('coffee-result-area');
var resLine1 = document.getElementById('resLine1');
var resLine2 = document.getElementById('resLine2');
if (isNaN(amount) || amount <= 0 || isNaN(ratio) || ratio <= 0) {
alert('Please enter valid positive numbers for both the amount and the ratio.');
return;
}
resultArea.style.display = 'block';
if (mode === 'findWater') {
var waterNeeded = amount * ratio;
resLine1.innerHTML = 'Coffee Grounds: ' + amount.toFixed(1) + ' g';
resLine2.innerHTML = 'Total Water to Pour: ' + waterNeeded.toFixed(0) + ' ml (g)';
} else {
var coffeeNeeded = amount / ratio;
resLine1.innerHTML = 'Total Water Volume: ' + amount.toFixed(0) + ' ml (g)';
resLine2.innerHTML = 'Coffee Grounds Needed: ' + coffeeNeeded.toFixed(1) + ' g';
}
// Scroll to result on small screens
resultArea.scrollIntoView({ behavior: 'smooth', block: 'nearest' });
}