How to use the coffee ratio calculator

Select your brewing method. Choose from Drip, Pour Over, French Press, AeroPress, Cold Brew and Espresso. Each method sets its own grind size and brew time.
Set your drink size. Pick the number of cups or enter a custom amount, such as 1.5 cups.
Choose brew strength. Mild, Balanced, Strong or Robust. Each uses a precise coffee-to-water ratio.
Select roast level. The calculator recommends the water temperature for your roast, from Light to Dark.
Press Calculate ratio. You get the coffee and water amounts, grind size and brewing instructions.
Copy, share or download. Copy the recipe text, share it, or save a PNG recipe card.

Switch between grams and ounces at any time with the Switch to oz / grams button.

How do you calculate a ratio for coffee?

Use a formula of 1 : x — one part coffee to x parts water.

A ratio of 1:15 means 1 g of coffee to 15 g (or ml) of water.
For example, 20 g of coffee × 15 = 300 g (or ml) of water.

This scales the recipe up or down without losing balance.

What is the optimal brewing temperature range?

The generally accepted range for hot brewing is 195–205 °F (about 90–96 °C). The Specialty Coffee Association's brewing standard sits inside it, at 92–96 °C.

Below about 195 °F (90 °C), extraction may be weak or sour.
Above about 205 °F (96 °C), you risk extracting bitter compounds.
Cold brew is the exception: it steeps in cold or room-temperature water.

Best brewing temperature by roast level

These are the temperatures the calculator gives for each roast level.

Roast level	Recommended temperature	Reason
Light roast	200–205 °F (93–96 °C)	Light roasts are denser, so a higher temperature helps pull flavours.
Medium-light roast	197–202 °F (92–94 °C)	Slightly hotter than medium keeps the brighter notes.
Medium roast	195–200 °F (90–93 °C)	A mid temperature balances acidity and sweetness.
Medium-dark roast	190–197 °F (88–92 °C)	A little cooler holds back the roasty bitterness.
Dark roast	185–195 °F (85–90 °C)	Dark roasts extract faster, so a cooler temperature prevents bitterness.

Recommended ratios for different brewing methods

Method	Typical ratio range	Notes
Pour-over / Drip	1:15 → 1:17	Balanced and clean flavours
French Press / immersion	1:13 → 1:15	Full body, steady contact
Espresso / concentrated	about 1:2	Highly concentrated under pressure
Cold brew (ready to drink)	1:8 → 1:15	Brewed at drinking strength and served over ice
Cold brew (concentrate)	1:4 → 1:8	Diluted with water or milk before drinking

The calculator takes its ratio from the strength you choose, from 1:17 (Mild) to 1:11 (Robust), and uses it for every method. The brewing method sets the grind, brew time and, for cold brew, the water temperature.

Espresso is brewed nearer 1:2, so treat the espresso result as a dose reference rather than a brew recipe.
Cold brew at these presets comes out ready to drink. For a concentrate, use about 1:4 to 1:8 and dilute it before serving.

How does changing the ratio affect flavour, strength and extraction?

A lower ratio (1:13) means more coffee per unit of water: stronger, heavier body, more intense flavour, with a risk of bitterness.
A higher ratio (1:17 or 1:18) gives a lighter, cleaner cup, with a risk of sour, weak under-extraction.
Brew ratio is the primary lever for strength, and it influences how extraction happens.

Should you change the ratio depending on roast level?

It can help, because roast affects extraction speed. The calculator adjusts only the water temperature by roast (see the table above) and leaves the ratio to the strength you pick, so make this change yourself:

Light roasts often taste better with a little more coffee, around 1:14–1:15.
Dark roasts extract faster and often work better around 1:16–1:17.

What else influences the ideal proportion?

Grind size: finer grinds extract faster, coarser grinds slower.
Roast level: darker roasts are more soluble and may need a looser ratio.
Brew time and method: longer immersion contact changes the optimal ratio.
Temperature stability: fluctuations reduce consistency.
Water quality and minerals: these affect extraction behaviour.
Altitude and environment: boiling point changes, so temperatures may need adjusting.

What tools help with precision and consistency?

Digital scale accurate to 0.1 g for coffee and water.
Temperature-controlled kettle to hit target temperatures reliably.
Timer for a consistent brew time.
Burr grinder for uniform particle size.
Refractometer or TDS meter for measuring brew strength and extraction yield.

How to tune your recipe when the brew does not taste right

Issue	Adjustment
Sour or weak	Tighten the ratio (more coffee or less water), raise the temperature slightly, grind finer.
Bitter or harsh	Loosen the ratio (more water), lower the temperature, grind coarser.
Inconsistent results	Change one variable at a time and keep a brewing log.

The Coffee Fuze pro tip for the perfect brew

Use freshly ground beans, filtered water and pre-heated equipment.
Maintain a steady temperature throughout brewing to extract sweetness and clarity.
Freshness, grind consistency and temperature control matter as much as ratio precision.

Baseline and example recommendation

Start at 1:15 as a general baseline.
For pour-over, explore 1:15 → 1:17 to taste.
For immersion and French Press, 1:13 → 1:15 is common.
Keep hot brews within 195–205 °F (about 90–96 °C), cooler for dark roasts and hotter for light roasts.
Refine ratio, temperature and grind until the cup tastes balanced.

Coffee to Water Ratio Calculator

Coffee Ratio Calculator

Your calculated ratio coffee recipe