Coffee Ratio Calculator
Dial in the perfect coffee-to-water ratio for pour-over, French press, AeroPress, cold brew, espresso and more.
Brewing for a number of cups?
Result
20.0 g (0.71 oz)
320 ml (10.8 fl oz)
1 : 16.0
3.6 tbsp
Based on ~5.5 g of ground coffee per level tablespoon; actual weight varies with roast and grind.
How the coffee ratio calculator works
A coffee-to-water ratio compares the weight of dry ground coffee to the weight of water, written as 1:x. Because water has a density of about 1 g/ml, a ratio of 1:16 means 1 gram of coffee for every 16 grams — or 16 ml — of water. The core formula is simply water = coffee × ratio, which rearranges to coffee = water ÷ ratio or ratio = water ÷ coffee depending on which value you already know.
Worked example: for a standard pour-over at a 1:16 ratio with 20 g of coffee, water = 20 × 16 = 320 g, which is 320 ml since water's density is 1 g/ml. That converts to about 10.8 fl oz of water and roughly 20 ÷ 5.5 ≈ 3.6 level tablespoons of ground coffee.
Each brew method has a typical range rather than one fixed number. Immersion methods like French press (1:15) and moka pots (1:10) tend to sit lower (more coffee per unit of water) than filter methods like drip machines (1:17), because contact time and extraction efficiency differ. Concentrated styles — espresso (1:2) and cold brew concentrate (1:5) — use far less water because they're diluted or sipped in small volumes; ready-to-drink cold brew (1:8) is brewed weaker so it doesn't need dilution.
The strength slider nudges the ratio up or down in half-point steps without changing brew method, so you can taste-test toward a bolder or lighter cup. The "number of cups" helper multiplies your cup size (240 ml is a common coffee-scoop standard, though many mugs hold 300-350 ml) by the number of cups you're brewing to fill in a target water amount automatically.
Tips: weigh coffee and water on a kitchen scale rather than measuring by volume — a tablespoon of coffee can vary from 5-6 g depending on roast density and grind size. Start near the middle of a method's typical range, then adjust up to half a ratio point at a time until the cup tastes balanced rather than sour (under-extracted) or bitter (over-extracted).
Coffee Ratio Calculator: frequently asked questions
What is a coffee-to-water ratio?
It is the weight of ground coffee compared to the weight of water, written like 1:16. A 1:16 ratio means 1 gram of coffee for every 16 grams (about 16 ml) of water. Lower numbers (like 1:2 for espresso) make a stronger, more concentrated brew; higher numbers (like 1:17) make it weaker.
What's the best ratio for pour-over coffee?
Most pour-over recipes fall between 1:15 and 1:17, with 1:16 as a solid all-purpose default. Move toward 1:15 for a bolder cup or 1:17 for a lighter, more tea-like cup, then adjust to taste using the strength slider.
How many tablespoons is 20 grams of ground coffee?
About 3.5-4 level tablespoons, using the common estimate of 5-6 grams per tablespoon. This varies with roast level and grind size, so a kitchen scale is always more accurate than scooping by volume.
How much water do I need for 4 cups of coffee?
It depends on your cup size. With the default 240 ml cup and a 1:16 ratio, 4 cups needs 960 ml of water and about 60 g of coffee. Change the cup size field if your mug or carafe uses a different volume.
Why does cold brew use a different ratio than hot coffee?
Cold brewing extracts more slowly, so cold brew concentrate is typically made much stronger (around 1:5) and diluted with water or milk before drinking, while ready-to-drink cold brew is brewed closer to 1:8 so it can be enjoyed without dilution.