Coffee Ratio Calculator
The calculator converts between coffee weight and water volume at the ratio you choose. Enter the water, the coffee or the number of cups and it fills in the rest.
Ratio is the fastest lever on strength. Grind and temperature shape the flavour, but the ratio decides whether the cup lands thin or full.
Coffee needed
31.3 g
≈ 5.2 tablespoons (≈6 g level)
Water needed
500 ml
1 : 16 · Formula: water ÷ ratio = coffee
Ground coffee retains about 2 ml of water per gram, so the cup holds less than you pour.
Ratios by brewing method
| Method | Ratio | For 500 ml of water |
|---|---|---|
| Pour over, filter | 1:16 | 31 g |
| French press | 1:15 | 33 g |
| AeroPress | 1:14 | 36 g |
| Moka pot | 1:10 | 50 g |
| Cold brew concentrate | 1:8 | 63 g |
| Espresso | 1:2 | 2 g of drink per 1 g of coffee |
How to read a ratio
1:16 means one gram of coffee for sixteen grams of water. Water is convenient because grams and millilitres match, so 500 ml is 500 g and the coffee comes to 500 ÷ 16 ≈ 31 g.
The smaller the second number, the stronger the brew. Moving from 1:17 to 1:15 noticeably thickens the cup, and 1:8 for cold brew produces a concentrate that is later diluted roughly one to one.
Spoons instead of scales
- A level tablespoon of ground coffee is about 6 g; heaped it reaches 10 g.
- A teaspoon holds roughly 2 g of ground coffee.
- Density varies by up to 30% between beans and grind sizes, so scales beat spoons.
- Without scales, measure once by spoon and remember the taste — then repeat the volume rather than the ratio.
How much drink you actually get
Ground coffee retains about two millilitres of water per gram. Brewing 30 g in a filter leaves roughly 60 ml in the bed, so 500 ml of water yields around 440 ml in the cup.
A French press behaves the same way, and a moka pot keeps some water in the lower chamber — the finished volume is almost always smaller than the water poured in.
Frequently asked questions
How much coffee do I need for 500 ml of water?
About 31 g at a 1:16 ratio. For a fuller cup use 1:15, which is 33 g.
What ratio should I use for a French press?
1:15 is the classic starting point — 33 g of coffee for 500 ml of water, steeped for about four minutes.
How many grams are in a tablespoon of coffee?
Roughly 6 g level. Heaped it can reach 10 g, which is why scales give more repeatable results.
Why is there less drink than water poured in?
The coffee bed holds about 2 ml of water per gram. With 30 g of coffee, around 60 ml never reaches the cup.
How do I scale cold brew?
A 1:8 ratio makes a concentrate — 63 g of coffee for 500 ml of water. Dilute it roughly one to one with water or milk before serving.
Updated: 2026-08-09