How the coffee ratio works
Coffee strength is set by the coffee-to-water ratio: water = coffee grams × ratio. A common starting point is 1:16 — so 30 g of coffee uses about 480 g (≈480 mL) of water. Lower ratios (1:14) brew stronger; higher (1:18) brew lighter.
The ratio is written as coffee:water, so 1:16 means one gram of coffee for every sixteen grams of water. Because one millilitre of water weighs one gram, 480 g and 480 mL are interchangeable here. A level tablespoon of ground coffee is 5 g to 7 g depending on grind and roast, and that spread alone can shift a cup from balanced to sour.
Ranges worth knowing: 1:14 to 1:15 for a strong pour-over, 1:15 to 1:17 for standard drip, 1:17 to 1:18 for a lighter cup, and roughly 1:8 for cold brew concentrate. Espresso is described the other way round, about 1:2 — 18 g in, 36 g out.
A quick pass through the grams to cups calculator saves a step later on.
How to use this calculator
Enter your coffee weight in grams and your ratio (the water part of 1:X). Typical ranges: 1:15–1:17 for drip and pour-over, around 1:8 concentrate for cold brew. Weighing beans and water gives the most repeatable cup.
Worked example: brewing for two people with a 500 mL carafe at 1:16, divide 500 by 16 to get about 31 g of coffee. Going the other direction, 60 g of coffee at 1:15 needs 60 × 15 = 900 g of water. The brewed volume in the cup is lower than the water poured: wet grounds retain roughly two grams per gram of coffee, so a 30 g dose keeps about 60 g back.
If a cup tastes bitter and drying the cause is usually over-extraction rather than the ratio — grind coarser before adding water; if it tastes thin and sour, grind finer or tighten the ratio to 1:15. For scaling recipes between weight and volume, the ml to grams calculator and the cups to grams calculator handle the rest of the kitchen.
Frequently asked questions
- What is a good coffee to water ratio?
- About 1:16 is a balanced starting point. Use 1:14 for stronger and 1:18 for lighter coffee.
- How much water for 30g of coffee?
- At 1:16, about 480 g or 480 mL of water.
- How do I calculate the ratio?
- Multiply the coffee weight by the water part of the ratio. 30 g × 16 = 480 g water.
- What ratio is best for cold brew?
- Cold brew concentrate is often around 1:8, diluted to taste before serving.
- Should I weigh the water or measure it in millilitres?
- Either works, because 1 mL of water weighs 1 g at normal brewing temperatures. Weighing is more reliable in practice, since a scale removes the guesswork of reading a jug and lets you pour in stages.