A cold brew ratio calculator helps you measure the exact amount of coarsely ground coffee and water needed for smooth, low-acid cold brew concentrate. Unlike hot brewing methods, cold brew steeps grounds in cold or room-temperature water for 12 to 24 hours, producing a concentrate that you dilute before serving. Getting the ratio right determines whether your batch tastes balanced and rich or weak and watery. Enter your desired volume and strength below for precise measurements.
Cold Brew Calculator
Serving Breakdown
Cost Per Serving
Quick Recipes
Storage & Shelf Life
Concentrate: Lasts 7-10 days in a sealed container in the refrigerator. Keep it undiluted for maximum freshness. Diluted cold brew: Best consumed within 2-3 days. Always store in a glass jar or airtight container. Discard if it tastes sour or develops an off smell.
How to Use the Cold Brew Ratio Calculator
Making cold brew at home is surprisingly simple, but getting the ratio of coffee to water right is the difference between a smooth, rich concentrate and a weak, flavorless batch. This cold brew ratio calculator removes the guesswork by computing exact measurements based on your desired volume, strength, and serving preferences.
Step 1: Set Your Brew Volume
Enter the total volume of cold brew you want to make. The default is 32 fluid ounces (about 946 ml), which fits a standard mason jar. Toggle between metric and imperial units with the switch at the top right. The calculator supports volumes from small single-serve batches up to large half-gallon batches for weekly meal prep.
Step 2: Choose Your Strength
Select one of three strength levels. Concentrate (1:5) produces a strong base meant to be diluted with water, milk, or ice before drinking — this is what most coffee shops make. Regular (1:8) gives a ready-to-drink cold brew with bold flavor. Light (1:12) creates a milder, refreshing brew similar in strength to standard iced coffee. The ratio refers to coffee grounds to water by weight.
Step 3: Pick a Steep Time
Steep time controls how much flavor and caffeine are extracted. A 12-hour steep produces a lighter, more delicate brew. The recommended 16-hour steep delivers balanced sweetness and body. An 18-hour steep draws out deeper chocolate and caramel notes. Going to 24 hours pushes into bold, intense territory that some drinkers find slightly bitter. Experiment to find your preference.
Step 4: Configure Dilution and Servings
If you are making concentrate, set the dilution ratio (1:1 or 1:2) to see how much concentrate and water go into each serving. Then pick your serving size — 8 oz, 12 oz, or 16 oz — to see how many servings your batch will yield. The serving breakdown section shows the exact pour amounts per glass.
Step 5: Estimate Your Cost Savings
Enter the price and weight of your coffee bag to calculate the cost per serving of homemade cold brew. Most home-brewed cold brew costs under $1 per serving compared to $4-6 at a coffee shop. The calculator shows your per-serving savings, helping you see how quickly a bag of quality beans pays for itself compared to buying cold brew daily.
Quick Recipes
Use the quick recipe cards to instantly load pre-configured amounts for a mason jar (32 oz), French press (34 oz), or large batch (64 oz). Each recipe auto-fills the volume and shows the corresponding coffee and water measurements. Click any recipe card to apply it, then adjust strength or steep time to your liking.
Frequently Asked Questions
Is this cold brew calculator really free?
Yes, the cold brew ratio calculator is completely free with no limits, no account, and no signup required. All calculations happen instantly in your browser. Use it as often as you like.
Is my data safe and private?
Absolutely. Everything runs locally in your browser using JavaScript. No data is sent to any server, stored, or shared. You can even use it offline once the page loads.
What is the best ratio for cold brew concentrate?
The most popular ratio for cold brew concentrate is 1:5 (one part coffee to five parts water by weight). This produces a strong concentrate meant to be diluted before drinking. For a lighter, ready-to-drink cold brew, use 1:8 or 1:12. This calculator lets you choose the strength that fits your preference.
How long should I steep cold brew?
Most cold brew recipes recommend 16 to 18 hours in the refrigerator. Shorter steeps (12 hours) yield a lighter, more tea-like flavor. Longer steeps (24 hours) extract more body and bitterness. The sweet spot for most people is 16 hours, which balances smooth flavor with full extraction.
How do I dilute cold brew concentrate?
A typical dilution ratio is 1:1 (equal parts concentrate and water, milk, or ice). If you prefer a lighter drink, use 1:2 (one part concentrate to two parts liquid). The calculator shows exactly how much concentrate and dilution liquid you need for your desired serving size.
How long does cold brew concentrate last?
Cold brew concentrate lasts 7 to 10 days when stored in a sealed container in the refrigerator. Undiluted concentrate keeps longer than diluted cold brew. Always discard it if it develops an off taste or sour smell.
Why does cold brew use so much more coffee than regular brewing?
Cold water extracts flavors much more slowly than hot water, so cold brew requires a higher coffee-to-water ratio to compensate. The resulting concentrate is then diluted before serving, so the final cost per cup is comparable to other brewing methods.
What grind size should I use for cold brew?
Use an extra coarse grind, similar to raw sugar or sea salt. A coarse grind prevents over-extraction during the long steep time and makes filtering easier. Fine grinds can produce a bitter, muddy cold brew that is hard to strain.