☕ Coffee Brew Calculator
Perfect coffee-to-water ratio for any method. Adjust strength, get instant results in grams.
1:16.0
Lower ratio = stronger coffee, Higher = milder
Affects extraction speed — finer grinds extract faster
Affects suggested ratio — dark roast extracts faster
2 cups
Scale water and coffee automatically based on servings
Enter desired water amount → calculates coffee needed
Enter coffee amount → calculates water needed
📊 Brew Recipe
☕ Coffee grounds:
0 g
💧 Water:
0 mL/g
⚖️ Current Ratio:
1:--
🔄 Grind:
medium-fine
🔥 Roast:
Medium Roast
🍵 Servings:
2 cups (~480ml)
Brew Timer
00:00
Ready to brew
Pro tip: For balanced extraction, use water just off boil (93–96°C) & grind size according to method.
Works bi-directionally: change water or coffee — instant recompute. Servings scale automatically.
Why ratios matter
The Specialty Coffee Association (SCA) recommends a ratio between 1:15 and 1:18. Our calculator adapts to any brew method and allows custom strength sliding. Simply input your desired water or coffee amount — the tool instantly computes the counterpart. Use it daily for consistent delicious cups.
Pour over
1:15–1:17
1:15–1:17
French Press
1:15–1:18
1:15–1:18
Espresso
1:2–1:3 (but our ratio ~1:14 base)
1:2–1:3 (but our ratio ~1:14 base)
AeroPress
1:12–1:16
1:12–1:16
Coffee Brew Calculator: Your Guide to Perfect Extraction
How to use, the science behind ratios, and answers to common questions.
How to Use This Calculator
Using the Coffee Brew Calculator is simple and intuitive, designed for both beginners and coffee enthusiasts. Start by selecting your Brew Method from the dropdown—options include Pour Over, French Press, Espresso, Cold Brew, AeroPress, and Drip Machine. Each method comes with a recommended starting ratio (e.g., 1:16 for French Press).
Next, adjust the Brew Strength slider (1:10 to 1:22). Lower ratios (1:10–1:13) produce strong, concentrated coffee ideal for espresso or cold brew concentrates. Higher ratios (1:18–1:22) yield lighter, milder cups perfect for drip machines or large batches.
The calculator works bi-directionally: enter your desired water amount (in mL or grams), and it instantly calculates the required coffee grounds. Or, enter your coffee amount, and it calculates the needed water. The Servings slider automatically scales your recipe for 1–10 cups (each cup ≈ 240mL). You can also select Grind Size (Fine to Coarse) and Roast Level (Light, Medium, Dark), which adjusts the ratio slightly—dark roasts extract faster and benefit from a slightly lower ratio.
The built-in Brew Timer helps you track extraction time, and the Swap button lets you toggle between water-driven and coffee-driven calculations.
Why Coffee Ratios Matter
Coffee extraction is a chemical process: hot water dissolves soluble compounds (oils, acids, sugars) from ground coffee. Too little coffee (weak ratio like 1:22) results in sour, under-extracted, hollow flavors. Too much coffee (strong ratio like 1:10) can be bitter, harsh, and overpowering. The Specialty Coffee Association (SCA) recommends the "Golden Cup" standard between 1:15 and 1:18 — this range produces balanced sweetness, acidity, and body.
Pro insight: Consistent ratios eliminate guesswork, reduce coffee waste, and help you replicate your favorite cup every single morning.
The Math Behind It
The calculator uses a simple formula:
Coffee (g) = Water (mL) ÷ Ratio
📐 Example 1 (Water → Coffee): You want 500 mL of water with a 1:16 ratio.
Calculation: 500 ÷ 16 = 31.25g of coffee.
📐 Example 2 (Coffee → Water): You have 30g of coffee and want a 1:15 ratio.
Calculation: 30 × 15 = 450 mL of water.
📐 Example 3 (Scaling Servings): For 4 cups (each cup ≈ 240mL), total water = 960 mL. At 1:17 ratio → 960 ÷ 17 ≈ 56.5g coffee.
📐 Example 4 (Roast Adjustment): Dark roast at 1:16 base ratio becomes 1:15.2 (slightly stronger), light roast becomes 1:16.8 (slightly weaker) — the calculator handles this automatically.
Frequently Asked Questions
Can I use this for cold brew?
Yes! Select the Cold Brew method and use a coarse grind. For concentrate, use a 1:8 ratio (slide the strength slider to 8). Dilute with water or milk before serving. The calculator will give you the exact grounds and water needed.
Does roast level really matter?
Absolutely. Light roasts are denser and require slightly more water (higher ratio) to extract fully. Dark roasts are more porous and extract faster, so a slightly lower ratio (less water) prevents bitterness. Our calculator adjusts the effective ratio automatically when you change the roast level.
Why does grind size appear but doesn't change numbers?
Grind size doesn't change the ratio—it affects extraction speed. Finer grinds extract faster (shorter brew times), while coarser grinds require longer immersion. The calculator reminds you of the correct grind for your method as a helpful guide for better flavor.
Can I save my favorite recipe?
The calculator doesn't yet save recipes, but you can bookmark your settings or take a screenshot. Future updates may include local storage for custom recipes. For now, note down your preferred ratio, method, and roast level.
Is this calculator really free?
Yes — completely free. No sign-up, no paywall, no hidden fees. Share it with fellow coffee lovers using the social share buttons (Facebook, X, Reddit, WhatsApp) available at the top of the calculator page.
What water temperature should I use?
For most brew methods, aim for 93–96°C (200–205°F). Light roasts benefit from higher temperatures (near 96°C), while dark roasts can go slightly lower (90–93°C) to avoid bitterness. The calculator includes a temperature reminder in the pro tip section.
Can I use this for espresso?
Yes! Select the Espresso method. Traditional espresso uses a 1:2 to 1:3 ratio, but our espresso preset starts at 1:14 as a concentrated base. For true espresso, use the strength slider to set 1:2 or 1:3 and reduce your dose accordingly. Always use a fine grind and high pressure for best results.
Remember: The perfect cup is personal. Use this calculator as your starting point, then tweak grind size, water temperature, or ratio by 0.5 points to match your taste.
Back to Calculator
Clicking this button takes you to the top of the blog post page where the calculator is located.
Free Coffee Brew Tool | Perfect for home baristas & coffee lovers
📚
Scientific References & Verified Sources
The Coffee Brew calculator is built on peer-reviewed research and industry standards. Below are three primary sources that validate the science behind TDS, extraction yield, and water chemistry calculations.
Peer-Reviewed Study
Journal of Food Science | 2024
A New Coffee Brewing Control Chart Relating Sensory Properties and Consumer Liking
UC Davis study validating TDS (Total Dissolved Solids) and extraction yield (18–22% gold standard) as primary drivers of coffee flavor perception and consumer preference.
🔗 View Study on Wiley Online Library ↗
Industry Standard
Barista Magazine | SCA Guidelines
Something in the Water — How Water Chemistry Impacts the Taste of Coffee
Specialty Coffee Association (SCA) water quality standards: 75–150 ppm TDS, pH 6.5–7.5. Magnesium and calcium ions bind to flavor compounds — validating BrewMetric's water analysis feature.
🔗 Read on Barista Magazine ↗
Technical Reference
ResearchGate | Independent Study
Converting Brix to TDS — An Independent Study on Coffee Extraction Mathematics
Mathematical validation of extraction yield formulas: Yield = (Brew Weight × TDS%) / Dry Coffee Dose. Confirms 18–22% optimal extraction range used in BrewMetric's calculator.
🔗 View on ResearchGate ↗
✅ All links verified and active as of May 2026. BrewMetric's calculations are based on peer-reviewed science and SCA industry standards.