Tool · Coffee
Pick how you brew — drip, espresso, French press or cold brew — and type in how much water you're using, and the calculator tells you how many grams of coffee to use, along with the grind, water temperature and time the method's own standard or maker prints.
Where does each number come from?
- How you brew
- Four methods. Drip covers any machine or pour-over cone with a paper filter. Espresso is a machine that pushes hot water through a puck of fine coffee under pressure. French press is the pot with the plunger. Cold brew is coffee steeped in cold water for most of a day, which makes a concentrate you then dilute.
- Water you're using
- In grams — a kitchen scale makes this easy, and a milliliter of water weighs a gram, so a measuring jug works too. For espresso the box changes to the weight of espresso you want in the cup, because that’s how espresso recipes are written: so much coffee in, so much drink out.
- Strength
- Three settings. The middle one is the method’s published figure; the other two nudge the coffee up or down by a tenth. Grind, temperature and time stay as printed. If a cup tastes sour or thin, the grind is usually the next thing to change, and the grind-size piece walks through it.
What moves the answer?
Every method is a ratio — grams of coffee to grams of water — and the calculator is just multiplying yours out. For drip, the standard is 55 grams of coffee for every liter of water, so 500 grams of water takes about 28 grams of coffee and a 12-ounce mug takes about 20. French press runs on the same standard, at a coarser grind and a longer steep. Espresso works the other way round, by weight of drink rather than water: 18 grams of coffee makes about 36 grams of espresso, a one-to-two ratio, in about half a minute. Cold brew concentrate goes the other way from everything else — about a gram of coffee for every 5.5 grams of water, so a liter of water takes about 180 grams of coffee, and then you cut the result with two parts water to one part concentrate.
Doubling both sides keeps the strength; the calculator does that for any amount. Very small or very large batches drain and steep at different speeds, though, so the printed time is a starting point and your own clock finishes it.
What does the calculator take as given?
- Drip
- Uses the Specialty Coffee Association’s standard for brewed coffee, 55 grams per liter of water at 90 to 96 degrees Celsius. It’s the industry’s published figure, and it’s the same one the cost-per-cup calculator runs on.
- Espresso
- Uses the worked example a machine maker, La Marzocco, prints in its guide to brew ratios: 18 grams of ground coffee to 36 grams of liquid espresso in 25 to 35 seconds. Ratios from one-to-one to one-to-four are all espresso; one-to-two is the middle of the range.
- French press
- Uses the same 55 grams per liter as drip, because the maker most people own, Bodum, prints a spoon rather than a weight — “one rounded tablespoon or one scoop of coarse ground coffee” for each four-ounce cup — with hot but not boiling water and a steep of at least four minutes. The grind, the temperature and the time here are Bodum’s; the weight is the SCA’s.
- Cold brew
- Uses Toddy’s instructions for its own brewer: 340 grams of coarse coffee to 1.9 liters of water, which Toddy also states as a gram of coffee to 5.5 milliliters of water, steeped 8 to 24 hours at room temperature and then diluted one part concentrate to two parts water or milk. The ratio on the page is for the concentrate, so it doesn’t compare with the hot methods until you’ve diluted it.
- What's left out
- Pour-over recipes from individual roasters, which used to be on this page and still sit in the brew ratios reference table with their quotes and dates. Water chemistry, which has its own piece. And taste, which is the point of all of it and the one thing the calculator can’t weigh.
The 500 grams and the 12-ounce mug are round figures to show the multiplication; your own numbers are whatever your scale and your brewer say, and the printed grind and time are where to start before you change one thing at a time.
Sources
- Specialty Coffee Association, SCA Standard 310-2021, Home Coffee Brewers: Specifications and Test Methods — 55 g per 1.000 kg of water; 90–96 °C. Read from a verbatim public mirror; the SCA’s own copy is member-only.
- La Marzocco Home, Using Espresso Brew Ratios, 10 November 2022 — “put 18g of ground coffee into it … we will pull 36g of liquid espresso in 25-35 seconds.”
- Bodum, French Press Coffee Makers — Instructions for use, leaflet ZP2018-000009 (V2.20190212) — “For each cup (1.25 dl or 4 oz), put 1 rounded tbsp or 1 BODUM scoop of coarse ground coffee into the pot”; “Pour hot (not boiling) water”; “Let the coffee brew for at least 4 min.”
- Toddy, Cold Brew System Brewing Guide, 2022 — “12 ounces (340 g) of coarsely ground coffee and 8 cups (64 fl. oz./1.9 L) of filtered water”; “a 1 to 5.5 metric ratio”; “Steep … 8 to 24 hours”; “1 part coffee concentrate to 2 parts water or milk.”
- Bills & Beans, Brew Ratios by Method: The Reference Table — every recipe, including the roaster recipes no longer on this page, with its quote and the date it was read.