A coffee to water ratio calculator does one multiplication: water = dose x ratio. The work is knowing which ratio your brewer takes, and the National Coffee Association publishes a different one for each method. Pour over is 1:13 to 1:16 by weight, French press is 1:10 to 1:16, cold brew is 1:4 to 1:5, espresso is 1:2 of dry coffee to liquid out, and drip is stated in volume as the golden ratio, 1 to 2 tablespoons of ground coffee per 6 fl oz of water (NCA). Pick the row, multiply, brew.
Skip the multiplication
Six methods, the published ratio prefilled for each, and dose, yield and ratio solved from whichever one you type.
The published ratio for every method
| Method | Ratio as published | Contact time | Water temperature | Published by |
|---|---|---|---|---|
| Drip | 1 to 2 tbsp ground coffee per 6 fl oz water (golden ratio) | about 5 minutes | not stated | NCA |
| Pour over | 1:13 to 1:16 by weight | 2 to 4 minutes | 90 to 96 C | NCA |
| French press | 1:10 to 1:16 by weight | about 4 minutes | 90 to 96 C | NCA |
| Cold brew | 1:4 to 1:5 by weight | about 12 hours | room temperature or cooler | NCA |
| Espresso | 1:2, dry coffee to liquid espresso | 20 to 30 seconds | not stated | NCA |
| AeroPress | 16 to 18g to the 4 mark on the chamber | 60 seconds, stir 3 seconds first | 85 C | AeroPress |
| Moka pot | set by the pot, not chosen | until the upper chamber fills | stovetop | Bialetti |
Sources for each row are listed at the bottom of this page. All were fetched 2026-08-18. Where a source does not state a figure, the cell says so rather than borrowing a number from a different method.
Water for a 20g dose, by ratio
| Ratio | Water for 20g | Where that ratio comes from |
|---|---|---|
| 1:2 | 40g | espresso, yield rather than water in |
| 1:4 | 80g | cold brew, strong end |
| 1:5 | 100g | cold brew, weak end |
| 1:10 | 200g | French press, strong end |
| 1:13 | 260g | pour over, strong end |
| 1:15 | 300g | middle of the pour over band |
| 1:16 | 320g | pour over and French press, weak end |
Multiplication only. Scale linearly for any other dose: a 30g dose at 1:15 is 450g of water.
The two ratios that are not really ratios
Espresso is the first exception. Its 1:2 is dose to liquid out of the basket, not dose to water going in, because some of the water stays in the puck. That is why an espresso ratio has to be measured on a scale under the cup and cannot be set by filling a reservoir.
Moka pot is the second, and it is more absolute. Bialetti's instructions are to fill the boiler with cold water up to the lower edge of the safety valve and fill the funnel filter with ground coffee without pressing it down. Both quantities are fixed by the geometry of your pot, so a moka pot does not have a ratio you choose; it has a ratio you discover by weighing what fits. Any calculator that offers you a moka ratio slider is inventing one.
Why the bands are wide, and how to move inside them
The published ranges are wide because they cover roast, grind, taste and brewer geometry all at once. Inside a band, more coffee per unit of water gives a stronger cup, and less gives a weaker one. That is a strength control, not an extraction control: extraction is governed by grind, time and temperature. Confusing the two is the most common reason people push a ratio to 1:10 on a pour over and end up with something strong and sour rather than strong and sweet.
The practical order is to fix your ratio in the middle of the published band, get grind and time into range, and only then move the ratio to suit your taste.
As an Amazon Associate, Barista Life earns from qualifying purchases.
Every gram-based ratio on this page needs a scale to exist at all: search coffee scales on Amazon. Links are searches, not stocked listings.
Related reading
FAQ
What is the correct coffee to water ratio? It depends on the method. The NCA publishes 1:13 to 1:16 for pour over, 1:10 to 1:16 for French press, 1:4 to 1:5 for cold brew and 1:2 for espresso, and states drip as 1 to 2 tablespoons per 6 fl oz of water.
How much water do I need for 20g of coffee? Multiply by the ratio: 260g at 1:13, 300g at 1:15 and 320g at 1:16. For cold brew at 1:4 it is 80g.
What ratio does a moka pot use? None that you choose. Bialetti's instructions fill the boiler to the lower edge of the safety valve and fill the funnel filter without pressing the coffee down, so the pot fixes both amounts.
Sources: the National Coffee Association publishes the pour over ratio of 1:13 to 1:16, 93 C plus or minus 3 C and 2 to 4 minutes (pour over), the French press ratio of 1:10 to 1:16 and about 4 minutes (French press), the cold brew ratio of 1:4 to 1:5 and about 12 hours (cold brew), the espresso ratio of 1 gram dry coffee to 2 grams brewed espresso in 20 to 30 seconds (espresso) and the drip golden ratio of 1 to 2 tablespoons per 6 fl oz with about 5 minutes of contact (drip). The AeroPress figures of 16 to 18 grams, water to the 4 mark, 185 F (85 C), a 3 second stir and a 60 second wait are from the manufacturer's own instructions (AeroPress). The moka pot instructions to fill to the lower edge of the safety valve and not to press the coffee down are from the Bialetti Moka Express manual (PDF). All fetched and cached 2026-08-18. Water weights are multiplication.
Barista Life runs on coffee people. Browse the Barista Life shop to support the site.
Get the good coffee stuff
One email a week: what we verified, what is worth buying, and what is not. No spam, unsubscribe any time.