Coffee Ratio Calculator
How much coffee for how much water, at any brew ratio — for filter, French press, pour-over or a full pot.
Brew ratio is written as coffee to water by weight, so 1:16 means one gram of coffee for sixteen of water.
How the coffee ratio calculator works
Brew ratio is written as coffee to water by weight, so 1:16 means one gram of coffee for sixteen of water. Weight rather than volume matters because beans vary enormously in density: a scoop of light roast weighs noticeably less than the same scoop of dark. Water is convenient here because one millilitre weighs one gram, so 500 ml is 500 g.
Ratios run roughly 1:15 to 1:17 for filter and pour-over, 1:12 to 1:15 for French press, and about 1:2 for espresso, which is a different extraction entirely. Weaker than 1:18 tends to taste thin, stronger than 1:12 muddy — though grind size and time matter as much as ratio.
Formula: coffee = water ÷ ratio
Worked examples
| Inputs | Coffee needed | Note |
|---|---|---|
| 500 ml at 1:16 | 31.3 g | 31.3 g — a balanced filter brew |
| A single 250 ml cup at 1:15 | 16.7 g | 16.7 g |
| A 1 litre French press at 1:13 | 76.9 g | 76.9 g — strong |
FAQFrequently asked questions
What is a good coffee to water ratio?
1:16 by weight for filter — 31 g of coffee to 500 ml of water. French press runs stronger at 1:12 to 1:15.
Why weigh rather than scoop?
Because bean density varies with roast and grind. The same scoop of light and dark roast can differ by several grams, which is enough to taste.
How much does a tablespoon of coffee weigh?
About 10 g level, though it varies with grind — another reason scales beat spoons.
Does one millilitre of water really weigh one gram?
Close enough for brewing. It is exact at 4°C and about 0.1% lighter at brewing temperature.
What ratio is espresso?
About 1:2 — 18 g in, 36 g out. It is a different extraction from filter and the ratios are not comparable.
Where these figures come from
- US FDA — Safe Minimum Internal Temperatures — the internal temperatures the roasting calculator targets
- NIST SP 811 — Guide for the Use of the International System of Units — the exact weight and volume conversions used throughout
- UK Food Standards Agency — food safety and labelling standards
Last checked: September 2026. Baking ratios follow standard baker's percentage practice; roasting guidance follows published safe internal temperatures.