Drinks
Cold Brew Ratio Calculator
For cold brew concentrate, use 1 gram of coarsely ground coffee for every 4 to 5 grams of water, the range given by the National Coffee Association. For 1 liter of water that is 200 to 250 grams of coffee. Steep for about 12 hours at room temperature or cooler, then strain and dilute to taste.
Coarsely ground coffee
Enter how much water you are using.
Show the math
Cold brew ratio chart
| Water | 1:4 | 1:4.5 | 1:5 |
|---|---|---|---|
| 250 ml | 62.5 g | 55.6 g | 50 g |
| 500 ml | 125 g | 111 g | 100 g |
| 750 ml | 188 g | 167 g | 150 g |
| 1,000 ml | 250 g | 222 g | 200 g |
| 1,500 ml | 375 g | 333 g | 300 g |
| 2,000 ml | 500 g | 444 g | 400 g |
| 4,000 ml | 1,000 g | 889 g | 800 g |
How the calculator works
Cold brew is measured by weight, coffee against water. The National Coffee Association gives the range as 1 gram of coffee to 4 to 5 grams of water. The calculator turns your water into grams and divides by the ratio you pick.
coffee in grams = water in grams / ratio
Water is the easy part to weigh without a scale, because 1 milliliter of water weighs 1 gram. A liter is 1,000 grams. A US quart is 946 grams, and a US cup is 237 grams. If you enter cups, quarts or fluid ounces, the calculator converts to milliliters first and treats each one as a gram.
The three settings cover the published range:
- 1:4 is the strongest. 1,000 g of water takes 250 g of coffee.
- 1:4.5 sits in the middle. 1,000 g of water takes 222 g of coffee.
- 1:5 is the lightest. 1,000 g of water takes 200 g of coffee.
The gap between the two ends is 50 grams of coffee per liter, which is a real difference in the cup and in what a batch costs you.
Worked example
You have a 2 quart pitcher and want to fill it most of the way, so you plan on 1.5 liters of water at 1:4.5.
- 1.5 liters of water weighs 1,500 g.
- 1,500 / 4.5 = 333 g of coffee.
- A standard 12 ounce bag holds 340 g, so this batch uses almost the whole bag.
Working the other way is just as useful. If all you have is one 12 ounce bag (340 g) and you want the strongest concentrate, multiply instead of dividing: 340 x 4 = 1,360 g of water, which is 1.36 liters. At 1:5 the same bag stretches to 340 x 5 = 1,700 g, or 1.7 liters.
The method
These are the steps from the National Coffee Association guide.
- Grind the beans coarsely.
- Put the grounds in your container and add the water slowly, stirring so that all of the grounds get wet.
- Cover the container. If it has no lid, use cheesecloth. In a French press, leave the plunger all the way up.
- Steep for about 12 hours, or overnight, at room temperature or in the refrigerator.
- Strain through a coffee filter or a sieve lined with cheesecloth. Strain a second time if the liquid is still cloudy. In a French press, push the plunger down slowly, then strain again if you need to.
- Throw out the grounds, or compost them.
You do not need special equipment. A cold brew maker, a French press, a carafe or a large jar all work. If your brewer has a filter bag or basket, you lift it out at the end and skip the straining.
Concentrate is meant to be diluted
At 1:4 to 1:5 you are making a concentrate, not a drink to pour straight. For comparison, the coffee to water ratio calculator on this site starts a drip machine at 1:15 and pour over at 1:16, so a 1:4 or 1:5 brew carries three to four times as much coffee for the same water.
The National Coffee Association says the concentrate is meant to be diluted with water or enjoyed over ice. It does not give a fixed dilution, and this page does not invent one. Start by tasting a small glass over ice, then add cold water or milk a little at a time until it is where you like it. Write down what worked. The next batch will be the same strength if you weigh the coffee and water again.
Grind and water
The source recommends starting with a coarse grind, like rock salt, and adjusting from there:
- Bitter or sour: the grind is too fine. Go coarser.
- Flat or watery: the grind is too coarse. Go a little finer.
Buy whole beans and grind them just before brewing if you can. A burr grinder gives more even pieces than a blade grinder, and even pieces steep at the same rate.
For the water, the same guide suggests filtered water where possible, and says to avoid distilled or softened water.
Paper or cloth filters
The filter changes the drink more than you might expect.
A cloth filter absorbs some of the oils and sediment and tends to give a smoother cup. Rinse and dry it after every use. The National Coffee Association suggests boiling a reusable cloth filter in fresh water for 10 minutes every six to eight weeks.
A paper filter removes more of the oils, which gives a cleaner, lighter cup. Unbleached paper can leave a papery taste, and rinsing the filter before you strain helps.
Tips and common mistakes
Stir when you add the water. Dry pockets of grounds do not brew, so the batch comes out weaker than the ratio says it should.
Do not change two things at once. If a batch is too strong, change the ratio and keep the grind and the time. If it is bitter, change the grind and keep the ratio.
Keep the time steady. The 12 hours is part of the recipe. A batch left for much longer at the same ratio will not taste like the last one.
Clean everything after each batch. Old grounds and coffee oils left in a jar or a filter make the next batch taste bitter.
Scale by weight, not by eye. Doubling a batch means doubling both numbers. The calculator and the chart above do that for you.
Frequently asked questions
What is the best coffee to water ratio for cold brew?
The National Coffee Association gives 1 gram of coffee to 4 to 5 grams of water, written 1:4 to 1:5. That makes a concentrate, which is meant to be diluted with water or served over ice.
How much coffee do I need for 1 liter of cold brew?
A liter of water weighs 1,000 grams. At 1:4 that is 250 grams of coffee, at 1:4.5 it is 222 grams, and at 1:5 it is 200 grams.
How long should cold brew steep?
About 12 hours of contact between the coffee and the water, according to the National Coffee Association. Overnight on the counter or in the refrigerator works.
What grind should I use for cold brew?
A coarse grind, about the texture of rock salt. If the brew tastes bitter or sour, grind coarser next time. If it tastes flat or watery, grind a little finer.
Is cold brew the same as iced coffee?
No. Iced coffee is brewed hot and then cooled. Cold brew never touches hot water: the grounds steep in cool water for hours, which gives a smoother, less bitter drink.