Use this coffee-to-water ratio calculator when you know either your brewing-water amount or your dry coffee dose. The default is 1:16.7, equivalent to about 60 grams of coffee per liter of water. It is a practical starting point for filter and immersion coffee, not a universal ideal.
Coffee ratio calculator
Choose what you know, enter the amount, and select a 1:X ratio.
For 250 g water at 1:16.7.
Precise result: 14.97 g. A practical scale reading is rounded to 0.1 g.
Water-volume conversions are approximate for brewing: 1 mL is treated as 1 g. US cups and US fluid ounces use NIST conversion factors.
The calculator uses input water, meaning the water poured into the brewer. Your finished drink will weigh less because the filter and wet grounds retain some water.
Quick coffee-to-water ratio chart
This table is the no-script backup and a fast reference for common input-water amounts.
| Water | 1:15 | 1:16 | 1:16.7 | 1:17 | 1:18 |
|---|---|---|---|---|---|
| 200 g or mL | 13.3 g coffee | 12.5 g | 12.0 g | 11.8 g | 11.1 g |
| 237 g or 1 US cup | 15.8 g | 14.8 g | 14.2 g | 13.9 g | 13.2 g |
| 250 g or mL | 16.7 g | 15.6 g | 15.0 g | 14.7 g | 13.9 g |
| 300 g or mL | 20.0 g | 18.8 g | 18.0 g | 17.6 g | 16.7 g |
| 355 g or 12 US fl oz | 23.7 g | 22.2 g | 21.3 g | 20.9 g | 19.7 g |
| 500 g or mL | 33.3 g | 31.3 g | 29.9 g | 29.4 g | 27.8 g |
| 1,000 g or 1 L | 66.7 g | 62.5 g | 59.9 g | 58.8 g | 55.6 g |
The Specialty Coffee Association explains that drip and immersion brewing ratios are commonly written as 60 g of coffee per liter of water, or 1:16.7. That supports the default, but it does not make other preferences wrong.
How the coffee ratio formula works
When you know water:
coffee grams = water grams / ratio number
For 300 g water at 1:16.7:
300 / 16.7 = 17.96 g coffee, rounded to 18.0 g.
When you know coffee:
water grams = coffee grams x ratio number
For 22 g coffee at 1:16:
22 x 16 = 352 g water.
Do not calculate with the number 1. The notation 1:16 means one mass unit of dry coffee for 16 mass units of input water.
Input water is not final cup size
A request for a "12-ounce cup" can mean either 12 fluid ounces of input water or 12 fluid ounces of finished coffee. They are not identical. Grounds and filter retain water, and retention changes with dose, grind, filter, and draining.
This calculator interprets a volume as input water. If you need a specific final drink volume, start with slightly more water, measure the actual beverage yield, and use that measured difference to plan the next brew.
What should 1:15, 1:16.7, and 1:18 taste like?
If brewing conditions are otherwise comparable:
- 1:15 uses more coffee per unit of water and usually makes a more concentrated cup.
- 1:16 is a common compact starting recipe. Hario publishes a small-dripper example using 12.5 g coffee and 200 g water.
- 1:16.7 equals about 60 g/L and is the calculator default.
- 1:17 uses slightly less coffee and can suit readers who prefer a lighter concentration.
- 1:18 is less concentrated, but it is not automatically weak or under-extracted.
Ratio and extraction are different. A longer ratio can extract more material from each gram while still producing a lower beverage concentration. Peer-reviewed UC Davis Coffee Center research found complex relationships among strength, extraction, sensory attributes, and consumer liking, including more than one preference cluster.
Change ratio for strength, not every flavor problem
| What you taste | First question | Better first move |
|---|---|---|
| Balanced but too intense | Is concentration higher than you enjoy? | Move from 1:16 toward 1:17 |
| Balanced but too light | Is concentration lower than you enjoy? | Move toward 1:16 or 1:15 |
| Sour, sharp, hollow | Did water pass too quickly or unevenly? | Keep ratio stable; grind finer or improve wetting |
| Dry, rough, bitter | Was flow slow or agitation excessive? | Keep ratio stable; grind coarser or reduce agitation |
| Weak and drying together | Is extraction uneven? | Improve distribution and flow before adding coffee |
Change one variable at a time. Correct arithmetic cannot rescue an unsuitable grind, clogged filter, unstable temperature, or uneven pour.
Which cup and ounce does the calculator use?
The unit menu uses US customary volume:
- 1 US cup = 236.5882 mL.
- 1 US fluid ounce = 29.5735 mL.
- 12 US fluid ounces = about 354.9 mL.
These factors come from the NIST Guide to the SI. A metric cup is commonly treated as 250 mL, so choose milliliters when a recipe uses that convention.
The tool approximates 1 mL of water as 1 g for kitchen brewing. Temperature and dissolved minerals change density slightly; use a scale when repeatability matters.
Why tablespoons are not included
A tablespoon measures volume, not mass. The grams in a spoon change with roast level, grind size, particle shape, settling, and whether the spoon is level or heaped. Converting water volume is dependable; converting an unspecified spoonful of coffee is not.
If you only own a scoop, weigh several typical scoops once and calculate their average mass. Then use that personal average, understanding that a different coffee or grind can change it.
Do not use this calculator unchanged for espresso
Filter and immersion recipes normally compare dry coffee with input water. Espresso recipes usually compare dry dose with beverage yield. An espresso listed as 18 g in and 36 g out uses a 1:2 beverage ratio, not 1:2 kettle water.
Cold-brew concentrate can also involve two calculations: the brewing ratio and the later concentrate-to-water or concentrate-to-milk dilution. This calculator can perform the initial arithmetic if you enter a custom ratio, but it does not design or validate a cold-brew food-safety process or a final dilution recipe.
A useful video explanation
James Hoffmann's Coffee Brewing Ratios Explained provides an accessible discussion of recipe ratios and brewing theory. Use it as an expert explanation rather than a binding standard, then test the calculated recipe with your own coffee, grinder, and brewer.
Frequently asked questions
How much coffee do I need for 250 mL of water?
At 1:16.7, use about 15.0 g coffee. At 1:16, use about 15.6 g. The calculator treats 250 mL of water as approximately 250 g.
How much coffee do I need for one US cup?
One US cup is 236.5882 mL. At 1:16.7, use about 14.2 g coffee. If your mug is labeled one cup but holds 250 mL or more, enter its actual measured capacity instead.
How much water do I need for 30 g of coffee?
Use 501 g at 1:16.7, 480 g at 1:16, or 510 g at 1:17. Your finished beverage will weigh less than the input water.
Is 60 g/L the same as 1:16.7?
Approximately. Divide 1,000 g water by 60 g coffee and the result is 16.666..., conventionally rounded to 1:16.7.
Does a higher ratio number mean stronger coffee?
No. In 1:X notation, a higher second number means more water for the same coffee dose, so beverage concentration generally moves lighter when other conditions are comparable.
The practical takeaway
Use the calculator to remove arithmetic, then let taste guide the next controlled change. Start around 1:16 to 1:17 for filter coffee, record the exact dose and water, and change ratio only when preferred concentration is wrong. If the flavor is sour, hollow, rough, or drying, investigate extraction before assuming the calculator failed.
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