Cold Brew Ratio Calculator

Cold Brew Ratio Calculator: calculate cold brew ratio for cooking and nutrition. Practical tips and worked examples.

A coffee brew ratio calculator determines the ideal quantity of coffee grounds to water for any brewing method, based on the golden ratio standard used by specialty coffee professionals. The brew ratio is expressed as 1:X, where X is the number of grams of water per gram of coffee. The Specialty Coffee Association (SCA) defines the golden cup standard as 55g of coffee per litre of water (1:18), but optimal ratios vary by method — espresso requires 1:2 to 1:3 (highly concentrated), while cold brew uses 1:4 to 1:8 (immersion extraction). Recipe Scale Calculator and Ingredient Weight Calculator provide related quantity and nutritional calculations.

Brew ratio is one of three variables that determine extraction — along with grind size and water temperature. For a given grind size and temperature, increasing the ratio (more water per gram of coffee) produces a weaker, lighter cup; decreasing it produces a stronger, potentially over-extracted cup. The relationship between ratio, extraction yield, and total dissolved solids (TDS) is the foundation of specialty coffee quality control.

Select your brewing method — each method has a recommended ratio range.
Enter the amount of coffee you want to make (in ml or cups).
The calculator applies the recommended ratio to give you the coffee dose in grams.
Or enter a custom ratio (1:15, 1:16, 1:17, etc.) to dial in your preference.
Grind your coffee to the appropriate grind size for the method (coarse for French press, fine for espresso, medium for filter).
Adjust ratio based on taste: too weak/watery → decrease ratio (more coffee); too strong/bitter → increase ratio (more water) or adjust grind coarser.

Brew ratio formula

Coffee dose (g) = Water (g) ÷ Brew ratio

Brew ratio = Water (g) ÷ Coffee (g)

Common brew ratios by method: Espresso 1:2–1:3 (20g coffee → 40–60g espresso); Filter/pour-over 1:15–1:17 (15g coffee → 225–255ml water); French press 1:12–1:15; Aeropress 1:10–1:16; Cold brew 1:4–1:8 (coarse, 12–24 hour steep); Moka pot 1:7–1:10.

Worked example: Making 300ml filter coffee at 1:16 ratio. Coffee dose = 300 ÷ 16 = 18.75g ≈ 19g. Use 19g of medium-ground coffee to 300g (300ml) water at 92–96°C.

Interpreting your brew ratio result

SCA golden cup standards

The Specialty Coffee Association (SCA) golden cup standard targets: Total Dissolved Solids (TDS) 1.15–1.35% for filter coffee; extraction yield 18–22% of coffee grounds. At 1:15–1:18 ratio with correct grind and temperature (92–96°C), most filter coffees fall within this range. Below 18% extraction = under-extracted (sour, weak, grassy). Above 22% = over-extracted (bitter, astringent, harsh). Adjust grind finer to increase extraction; coarser to reduce. Adjust ratio to balance strength independently of extraction percentage.

Food tips and best practices

Use a kitchen scale accurate to 0.1g for coffee dosing — a 2g variation in an 18g dose changes the ratio by approximately 11% and noticeably affects cup quality.
Water temperature matters as much as ratio — 92–96°C is optimal for most filter coffee; lower temperatures under-extract, higher temperatures over-extract.
Freshly roasted coffee (7–21 days post-roast) produces significantly better extraction than very fresh (too much CO₂ causes uneven extraction) or stale (volatile aromatics depleted) beans.
Grind immediately before brewing — pre-ground coffee loses approximately 60% of its volatile aromatics within 15 minutes of grinding.
For espresso, the ratio is measured by yield weight not water volume — pull your shot until the espresso output reaches your target weight (typically 2–3× the dry coffee dose).

A 1g variation in coffee dose changes extraction TDS by approximately 0.04% — detectable by trained tasters but marginal for most drinkers; a 2–3g variation is clearly noticeable.
Espresso at 1:2 ratio (20g coffee, 40g output) has approximately 8–12× higher TDS than filter coffee at 1:16 — it is not more caffeinated per ml but contains 2–3× more caffeine per serving than a typical filter coffee serving.
Cold brew at 1:4–1:8 ratio produces a concentrate that is typically diluted 1:1 with water or milk before serving — effective final ratio is 1:8 to 1:16, similar to hot filter coffee.
Global coffee consumption is approximately 10 million tonnes per year (ICO, 2023) — making coffee the most widely traded tropical commodity after crude oil by value.

Common mistakes to avoid

Measuring coffee by volume (tablespoons, scoops) rather than by weight — coffee density varies by 50% between roast levels and grind sizes; weight is the only consistent measure.
Using boiling water (100°C) for filter coffee — this over-extracts bitter compounds; allow boiled water to cool to 92–96°C for 30–60 seconds before pouring.
Assuming a weaker cup is always produced by a coarser grind — ratio and grind both affect strength but in different ways; dial in one variable at a time.
Using the same ratio for different coffee origins and roast levels — lighter roasts typically require finer grind or longer brew time to achieve the same extraction as darker roasts.

Caffeine content in coffee varies significantly by variety, roast level, brewing method, and dose. The FDA considers up to 400mg caffeine per day safe for healthy adults; 200mg per day for pregnant women. A standard 250ml filter coffee contains approximately 80–150mg caffeine depending on dose and method. This calculator provides brew ratio guidance only — individual caffeine sensitivity varies significantly. Consult a healthcare provider if you have health conditions affected by caffeine.