Coffee to Water Ratio Calculator

Get the same great cup every time by brewing to a ratio. Choose your method and strength, enter how much coffee you want to make — or how much ground coffee you have — and the calculator gives exact grams of coffee and water.

Why brew coffee by ratio

The coffee-to-water ratio is the single biggest factor in how strong your coffee tastes. Measuring with a kitchen scale instead of scoops removes guesswork: different beans and roasts have different densities, so a scoop of dark roast weighs less than a scoop of light roast. Once you find a ratio you like, you can scale it to any amount — one mug or a full carafe — and get the same strength. The calculator does the arithmetic and adjusts for stronger or milder preferences.

Standard ratios by brew method

The Specialty Coffee Association's long-standing “Golden Cup” recommendation of about 55 grams of coffee per litre of water works out close to 1:18. Many home brewers prefer slightly stronger, around 1:15 to 1:16.

Worked example

For two 240 ml mugs of pour-over at 1:16, you need 480 ml of water and 480 ÷ 16 = 30 g of coffee — about five and a half level tablespoons of ground coffee. If you like it a little stronger, the “stronger” setting raises the coffee to 33 g for the same water. If instead you have only 20 g of beans left, switch to “ground coffee I have” to see that it makes 320 ml at the same ratio.

Grams, millilitres and tablespoons

For brewing, one millilitre of water weighs one gram, so you can weigh water directly on the scale while pouring. Ground coffee is less predictable by volume: a level tablespoon holds roughly 5 to 6 grams depending on grind and roast. The calculator converts to tablespoons as a rough guide, but a scale accurate to 0.1 gram is one of the best inexpensive upgrades for home coffee.

Adjusting taste beyond ratio

• Too weak or watery: use more coffee (a lower ratio number) or grind finer.
• Too strong or heavy: use less coffee or add hot water after brewing.
• Sour or thin: often under-extracted — grind finer, brew longer or use hotter water (around 195–205 °F / 90–96 °C).
• Bitter or harsh: often over-extracted — grind coarser, shorten the brew time or lower the water temperature slightly.
• Change one thing at a time so you know what made the difference.

Cold brew ratios

Cold brew steeps coarsely ground coffee in cold or room-temperature water for 12 to 24 hours. A concentrate at 1:4 to 1:8 is strong and is usually diluted with water or milk before drinking — often one part concentrate to one or two parts water. A ready-to-drink batch at around 1:12 needs no dilution. Filter it well and keep it refrigerated, covered, for up to about a week or two; flavour fades over time.

Espresso ratios

Espresso uses a much lower ratio because it is a concentrated drink, and it is measured by the weight of the liquid espresso rather than the water used. A “normale” shot at around 1:2 — for example 18 grams of coffee yielding 36 grams of espresso in 25 to 30 seconds — is a common starting point. Ristretto shots use about 1:1 to 1:1.5; lungo shots 1:3 or more.

Grind size by method

Ratio and grind size work together: the finer the grind, the faster the water extracts flavour. French press and cold brew use a coarse grind similar to sea salt; drip machines and flat-bottom pour-over use medium; cone pour-overs such as the V60 use medium-fine; AeroPress ranges from fine to medium depending on the recipe; moka pots use fine; and espresso needs a very fine, consistent grind from a capable burr grinder. If you change method, change both the ratio and the grind, then fine-tune by taste.