Formula
Coffee in grams is the water in grams divided by N, where the ratio is 1:N. The other way, water is coffee times N. Grams per litre is 1,000 divided by N. Millilitres of brew water are treated as grams. Retained water is coffee times the absorption factor, and the yield is water minus that, unless you set the ratio to mean beverage out. In that mode the result is the liquid weight, which is how an espresso 1:2 is usually written: 18 g of coffee, 36 g in the cup.
coffee = water / N
g/L = 1,000 / N
yield = water − coffee × absorption
Grind, time, and temperature move extraction at the same ratio. SCAA’s contact-time note is 1–4 minutes for a fine pour-over grind, 4–6 minutes for drip, and 6–8 minutes for a coarse immersion grind, with water at 200°F ± 5° where it meets the coffee. Weighing beats scooping. The scaled cups below use a US cup of 8 fl oz.
Worked examples
1:16 and 500 g water. 31.25 g coffee. At 2 g retained per gram, yield 437.5 g.
1:15 and 350 mL. 23.33 g. 1:12 and 1,000 g. 83.33 g. 60 g/L is 1:16.67. 12 fl oz at 55 g/L is 19.52 g. 4 US cups at 1:16 is 59.15 g. 30 g at 1:16 needs 480 g of water, 16.23 fl oz.
Reference
SCAA Golden Cup, 23 December 2015: 55 g/L ± 10 percent. That band is 49.5 to 60.5 g/L.
| US cups at 1:16 | Coffee |
|---|---|
| 1 | 14.8 g |
| 2 | 29.6 g |
| 4 | 59.1 g |
| 6 | 88.7 g |
| 8 | 118.3 g |
| 10 | 147.9 g |
| 12 | 177.4 g |
Questions
How much coffee per cup?
A US cup on this page is 8 fl oz, 236.588 mL. At 1:16 that is about 14.8 g of coffee. A coffee-maker cup is often 5 to 6 fl oz, so count the carafe in fl oz or grams instead of trusting the cup mark.
What is the best coffee to water ratio?
Taste decides. The SCAA Golden Cup standard of 23 December 2015 recommends 55 g of coffee per litre of water, plus or minus 10 percent, as the ratio that can land in its brew-strength box. That is about 1:18, and the band is about 1:16.5 to 1:20.
How many tablespoons of coffee per cup?
About one level tablespoon if you assume 5 g per tablespoon and a US cup at 1:16. That 5 g is an assumption. Roast and grind change the volume of a spoon. Weigh it.
How much coffee for a 12 cup pot?
If the pot is 12 US cups, 96 fl oz, at the Golden Cup 55 g/L the dose is about 156 g. If each cup mark is 5 or 6 fl oz, use that volume instead. The page will not guess the mark.
How much coffee for a French press?
The Golden Cup ratio is the sourced starting point for brewed coffee generally. A stronger 1:12 is a number you can type. It is not a separate standard on this page.
What is the golden ratio?
SCAA’s Golden Cup document says 55 g/L ± 10 percent, with brew strength 11.5 to 13.5 g/L TDS from an extraction of 18 to 22 percent, and water at 200°F ± 5° at contact. The ratio is the part this page uses.
How much water does coffee absorb?
The default is 2 g of water retained per gram of coffee, labelled approximate. Brewed yield is the water you started with minus that retained water.
Sources
- Specialty Coffee Association of America, Golden Cup Standard, 23 December 2015. Coffee-to-water ratio 55 g/L ± 10 percent. Brew strength 11.5 to 13.5 g/L TDS from 18 to 22 percent extraction. Water 200°F ± 5° at contact. Contact time 1–4 minutes fine, 4–6 drip, 6–8 coarse.
- 1 US fl oz = 29.5735 mL. 1 oz = 28.3495 g. 1 US cup = 236.588 mL. Water at brew temperature is taken as 1 g/mL.
- Tablespoons use an assumed 5 g. Absorption defaults to 2 g of water per gram of coffee and is labelled approximate. No other brew-method ratio is offered as a sourced preset.