Brewing Ratio Calculator

Perfect Brew Ratio Calculator

Optimize extraction for Pour-over, French Press, and Drip Coffee.

Brewing coffee is a science of balance. The “Ratio” is simply the relationship between the amount of ground coffee and water. Too much water makes it weak and bitter; too little makes it sour and overpowering. This tool calculates the ideal coffee-to-water ratio based on your brew method and desired strength, ensuring consistent, balanced flavor every time.

*Standard mug is approx 250ml – 300ml

Strong (1:10) Balanced (1:16) Weak (1:20)

You Need

15.0 grams coffee

To Brew With

250 ml water

Target Profile

Balanced, clear, distinct notes.

Visualizing Coffee Strength

Where does your current setting sit on the flavor spectrum? Use this visual guide to understand the trade-off between body and clarity.

1:16.5
Rich Watery
Cold Brew / Ristretto (1:5 – 1:12)
Golden Cup Standard (1:15 – 1:17)
Tea-Like (1:18 – 1:22)

Ratio Reference Table

Different brew methods require different ratios because of how long the water stays in contact with the coffee.

Brew Method Ideal Ratio Grind Size Flavor Profile
Pour-Over 1:15 – 1:17 Medium-Fine Clean, aromatic, highlights acidity.
French Press 1:12 – 1:15 Coarse Heavy body, rich, textured.
Auto Drip 1:16 Medium Standard balanced cup.
AeroPress 1:12 – 1:16 Medium-Fine Versatile; closer to 1:12 creates a concentrate.
Cold Brew 1:8 (Concentrate) Extra Coarse Smooth, low acid, very strong.

The Math Behind the Brew

If you don’t have this tool handy, you can calculate it manually using a simple division formula. Most coffee professionals measure in grams because volume (tablespoons) is inaccurate due to bean density.

Water Weight (ml) ÷ Ratio Number = Coffee Weight (g)
Example: 250ml ÷ 16 = 15.6g

How to Use This Tool

1
Select Your Method: Choose how you are brewing. This automatically sets a recommended starting ratio range (e.g., French Press needs more coffee than a Pour-Over).
2
Input Water Amount: Decide how much coffee you want to drink. Enter the milliliters (e.g., 250ml for a mug) or select “Cups” if measuring by standard 8oz cups.
3
Adjust Strength: Use the slider to fine-tune.
• Slide Left (Lower Number) for stronger, punchier coffee.
• Slide Right (Higher Number) for lighter, tea-like coffee.
4
Weigh & Brew: Weigh your beans to match the output number. Grind them fresh, and pour your specific amount of water.

Frequently Asked Questions

Why is my coffee bitter?
Bitterness usually indicates over-extraction. This means the water took too much flavor from the coffee, pulling out the harsh tannins.

The Fix: Try coarsening your grind size, lowering your water temperature slightly, or using a “weaker” ratio (e.g., move from 1:15 to 1:16).
Why is my coffee sour?
Sourness indicates under-extraction. The water didn’t spend enough time with the coffee to pull out the sugars that balance the natural acids.

The Fix: Try a finer grind size, hotter water, or a “stronger” ratio (e.g., move from 1:17 to 1:15).
Can I use tablespoons instead of a scale?
You can, but it is not recommended for consistent results. A tablespoon of dark roast weighs significantly less than a tablespoon of light roast because of density.

Rule of Thumb: If you absolutely have no scale, a standard tablespoon holds roughly 5g-6g of ground coffee. So for a 1:16 ratio and a standard mug (250ml/15g coffee), you would need about 3 level tablespoons.
Does roast level affect the ratio?
Yes! Light Roasts are denser and harder to extract, often benefiting from a higher ratio (1:17) and hotter water. Dark Roasts are more soluble and can easily become bitter, so they often taste best with a tighter ratio (1:15) but cooler water temps.
What is the “Golden Cup Standard”?
The Specialty Coffee Association (SCA) defines the Golden Cup Standard as a ratio of roughly 1:17 to 1:18 (55g-60g of coffee per liter of water). This is considered the optimal balance for most palates, ensuring the coffee strength is between 1.15% and 1.35% Total Dissolved Solids (TDS).