How much coffee do you need for 350 ml of water? Many brewers use about one gram of coffee for every 16 grams of water. The Coffee Ratio Calculator does that math for you and turns it into a clear recipe.
It suits home brewers, new espresso owners, and anyone who wants the same cup twice. You pick a brew method, enter one amount, and read three result cards.
Table of Contents
- What the Calculator Does
- How to Use It, Step by Step
- The Coffee Ratio Formula
- Worked Example
- How to Read the Results
- Choosing a Ratio for Your Brew Method
- Tips for a Steadier Cup
- Limitations and Assumptions
- FAQs About the Coffee Ratio Calculator
What the Calculator Does
The tool scales a coffee recipe from either the water you have or the coffee you want to use. It uses a ratio written as 1 : X. Here X is the parts of water per part of coffee.
- Required Coffee Grounds: the dose, shown in grams to one decimal.
- Required Water Volume: milliliters plus US fluid ounces, each to one decimal. A whole amount such as 350 ml shows no decimal.
- Brewing Ratio: the ratio you used, shown as 1 : X.
- Five brew presets and a custom option fill in the ratio for you.
- Results update as you type or change a menu. The Calculate Coffee Brew Recipe button also runs the math.
How to Use It, Step by Step
- Choose a Brewing Method. The ratio box below fills in automatically. Pick Custom Ratio to keep your own number.
- Choose Calculate Based On. Water Volume starts from your water. Coffee Ground Dose starts from your coffee.
- Enter the Quantity (grams / ml). The sample is 350. Water mode accepts 5 to 10,000 ml, and coffee mode accepts 5 to 1,000 g.
- Check the Water Ratio Parts (1 : X) box. The sample is 16, and it accepts any value from 1 to 30.
- Read the three cards. They refresh on every change, and the button repeats the same math.
The Coffee Ratio Formula
The math is plain division and multiplication. If you start with water, the tool divides by the ratio. If you start with coffee, it multiplies by the ratio.
Coffee Grounds (g)×Water Parts (X)=Water (ml)
- Water mode: grounds (g) = water (ml) ÷ X.
- Beans mode: water (ml) = grounds (g) × X.
- Fluid ounces = water (ml) ÷ 29.5735.
The tool treats 1 ml of water as 1 gram. That is a close match for water at room temperature. The 29.5735 figure is the number of milliliters in one US fluid ounce.
Worked Example
Dana wants to brew 350 ml of pour over with the default 1:16 ratio. She leaves the mode on Water Volume.
| Result | Calculation | Output |
|---|
| Required Coffee Grounds | 350 ÷ 16 = 21.875 | 21.9 g |
| Required Water Volume | 350 rounded; 350 ÷ 29.5735 | 350 ml (11.8 fl oz) |
| Brewing Ratio | Ratio box value | 1 : 16 |
Now try the other mode. Omar has 20 g of coffee and keeps 1:16. He switches to Coffee Ground Dose and enters 20. The tool shows 20.0 g, 320 ml (10.8 fl oz), and 1 : 16.
How to Read the Results
Required Coffee Grounds is the amount to weigh on a kitchen scale. A scale is more repeatable than scoops. Grind size and roast change how much fits in a scoop.
Required Water Volume is the total water you pour. In beans mode it can be a large number, so check that your brewer can hold it. The fluid ounce figure is only a convenience for US measuring cups.
The ratio card repeats your setting. If you type 15.5, the card reads 1 : 15.5. Grounds and water both keep one decimal, so tiny doses show rounded.
Choosing a Ratio for Your Brew Method
The presets give a starting point, not a rule. Taste and equipment vary a lot. A higher second number means more water and a lighter cup. A lower one makes a stronger cup.
| Preset | Ratio | 350 ml of Water Needs |
|---|
| Pour Over / Drip | 1:16 | 21.9 g |
| French Press | 1:15 | 23.3 g |
| Chemex | 1:17 | 20.6 g |
| Espresso (Dose to Shot Yield) | 1:2 | 175.0 g |
| Cold Brew Concentrate | 1:8 | 43.8 g |
The espresso row looks odd on purpose. A 1:2 espresso ratio usually means liquid in the cup, not water poured through the puck. Picking it shows a note and relabels the water card as Water or Shot Yield (1 ml = 1 g). Use Coffee Ground Dose instead. An 18 g dose shows 36 ml, or 1.2 fl oz.
Planning other kitchen math? The baking pan converter and the pizza size calculator cover pans and pies. To plan how much water you drink in a day, see the water intake calculator.
Tips for a Steadier Cup
- Weigh both coffee and water when you can, using the same scale.
- Change one thing at a time, such as the ratio or the grind, so you know what helped.
- Keep notes on what you liked, then reuse that ratio.
For daily energy needs, the calorie calculator is a separate tool. More everyday tools sit in the health and fitness calculators hub.
Limitations and Assumptions
- The tool does no strength, extraction, or taste scoring. It only multiplies or divides.
- It counts 1 ml of water as 1 gram and ignores water that grounds absorb.
- A blank, text, or out-of-range quantity or ratio shows a message and N/A in all three cards. Nothing is guessed.
- Water is entered in milliliters only. There is no ounce input, and the tool does no real density conversion.
- Espresso uses the same grounds and liquid math. There is no separate shot yield mode.
- Results are general guidance. Beans, water, and gear all change the final taste.
FAQs About the Coffee Ratio Calculator
What is a good coffee to water ratio?
Many brewers start near 1:16, which is about 62 g of coffee per liter of water. Some prefer 1:15 for a bolder cup or 1:17 for a lighter one.
Does the tool use grams or milliliters?
It treats them as the same for water, so 350 ml and 350 g give identical results. Coffee grounds are always in grams.
Can I use my own ratio?
Yes. Just edit the Water Ratio Parts box, and the Brewing Method menu switches to Custom Ratio. A value that matches a preset, such as 15, selects that preset again.
Why does the espresso preset give odd numbers in water mode?
The 1:2 espresso ratio compares coffee to the liquid shot in the cup. In water mode the tool still divides the quantity by 2. So 350 ml gives 175.0 g of grounds, which no one would brew.
How do I scale a recipe for a bigger pot?
Keep the same ratio and change only the quantity. For a 1,000 ml batch at 1:16, the tool gives 62.5 g of grounds and 33.8 fl oz. Weigh it for a close match.
Do the results change with roast or grind size?
No. The tool only does ratio math. Roast, grind, water temperature, and brew time all change taste.
This calculator gives general estimates only and is not medical advice. Reviewed for general accuracy by Prof. Dr. Khalil Mudassar, PhD.