Last updated: August 15, 2026
Cold Brew Ratio Calculator
Creators
Dharmendra SinghReviewers
Creators
Dharmendra SinghReviewers
Quick Answer
The cold brew ratio is calculated with **coffee = brew water ÷ ratio**, using typical ready-to-drink ranges near 1:14 to 1:16 and concentrate ranges near 1:4 to 1:8. For planned dilution, the calculator first finds brew water with **brew water = final volume ÷ (1 + dilution ratio)**, then calculates the coffee dose in grams.
To calculate cold brew, divide the brew water by your chosen ratio, and if you want concentrate with dilution, first divide the final drink volume by one plus the dilution ratio.
Key Takeaways
- Cold brew ratios are best planned by weight, not scoops or tablespoons.
- Ready-to-drink cold brew often sits around 1:14 to 1:16 water to coffee.
- Concentrate ratios such as 1:5 need planned dilution to reach serving strength.
- Changing ratio is usually a cleaner adjustment than dramatically changing steep time.
- Refrigeration after straining preserves flavor and improves food safety.
Creators
Dharmendra SinghReviewers
Creators
Dharmendra SinghReviewers
Formula
coffee = brew water ÷ ratio; brew water = final volume ÷ (1 + dilution ratio) for concentrate
Where:
- C=Coffee dose(g)
- W=Brew water(mL)
- R=Water-to-coffee ratio(mL/g)
Worked Examples
Ready-to-drink 1 liter batch
A classic ready-to-drink cold brew brewed at 1:15.
- 1Target final volume = 1000 mL.
- 2Ready-to-drink style uses the final volume as brew water.
- 3Coffee = 1000 ÷ 15 = 66.7 g.
- 4Dilution water = 0 because the brew is already drinking strength.
- 5You will steep 66.7 g coffee in 1000 mL water and strain to yield about 1 liter.
1 liter of 1:1 diluted concentrate
Brew concentrate at 1:5, then dilute one-to-one for serving.
- 1Finished beverage target = 1000 mL.
- 2With 1:1 dilution, half the beverage is concentrate and half is added water.
- 3Brew water = 1000 ÷ (1 + 1) = 500 mL.
- 4Coffee = 500 ÷ 5 = 100 g.
- 5Dilution water = 1000 − 500 = 500 mL.
500 mL stronger balanced batch
A smaller batch brewed at 1:12 for a fuller cup.
- 1Target volume = 500 mL.
- 2Coffee = 500 ÷ 12 = 41.7 g.
- 3Water remains 500 mL because the brew is not diluted.
- 4Coffee loading per liter = 41.7 × 2 = 83.4 g/L.
Introduction
A cold brew ratio calculator helps you choose the right coffee-to-water relationship before you grind a single bean. Cold brew is extracted with time rather than heat, so small changes in ratio have a big impact on body, sweetness, bitterness, and how much dilution the final drink needs. This calculator works for both ready-to-drink batches and concentrate. Enter the amount of finished coffee you want, pick a realistic brew ratio, and the tool returns the exact grams of coffee, brew water, and any dilution water needed for serving.
What a cold brew ratio actually means
Cold brew ratios are usually written as water to coffee by mass. A 1:15 ratio means 15 grams of water for every 1 gram of coffee. Because water is close to 1 gram per milliliter, home brewers can use milliliters and grams interchangeably for planning. Lower ratios such as 1:5 or 1:8 make concentrate, while higher ratios such as 1:14 to 1:16 are usually ready to drink.
The formula behind the calculator
The core formula is coffee = brew water ÷ ratio. For ready-to-drink cold brew, the finished volume is the brew-water volume. For concentrate, the calculator first backs out the concentrate volume from the finished target using brew water = final volume ÷ (1 + dilution ratio), then applies the coffee formula. This keeps the total beverage volume honest when you plan dilution ahead of time.
How to use the calculator step by step
Start with the amount of cold brew you want to serve, not the amount of coffee you feel like grinding. Choose whether you want a ready-to-drink batch or concentrate. Pick a ratio that matches your grind size and flavor goal, then decide whether the concentrate will be diluted 1:1 or more lightly. The calculator converts those choices into exact water and coffee numbers so you can batch consistently.
Grind size, steep time, and extraction
A coarser grind and a 12- to 18-hour steep are the most forgiving combination for cold brew. Finer grinds can increase strength quickly, but they also trap liquid and may over-extract if left too long. Most brewers find that strength changes more predictably by adjusting the ratio than by steeping for dramatically longer than 18 hours.
Concentrate versus ready-to-drink
Concentrate makes sense when you want a compact batch for storage or when you plan to serve the drink over ice, milk, or tonic. Ready-to-drink ratios save a step because the brew comes out near serving strength already. Neither style is inherently better; the better choice is the one that matches how you will pour the coffee after straining.
Practical tips for smoother cold brew
Use filtered water, a burr grinder, and a container large enough for the coffee bed to expand. Stir just enough to fully wet the grounds. After straining, taste before diluting further because different beans hold on to liquid differently. If the cup tastes flat rather than bitter, increase the coffee dose or shorten dilution instead of steeping for a full extra day.
Common mistakes that throw the ratio off
The most common error is measuring coffee by scoops instead of by weight. Another is forgetting that concentrate will be diluted later, which leads people to under-dose the brew water. Very fine grinds can also make the brew feel stronger even when the actual ratio has not changed, because fines keep extracting and are harder to strain out cleanly.
Storage and food-safety notes
Cold brew is low-acid but not shelf-stable at room temperature. Strain it, refrigerate it promptly, and keep containers clean to reduce off-flavors and contamination risk. The FDA and common industry guidance favor refrigeration and use within about a week for the best flavor. If milk or cream is added, treat the drink like any other dairy beverage and consume it much sooner.
Quick Reference Card
Cold Brew Quick Reference
Quick reference • Cold Brew Ratio Calculator
Coffee (g) = Brew water (mL) ÷ ratio; for concentrate, brew water = final volume ÷ (1 + dilution ratio)Valid range: Ready to drink: 1:14 to 1:16. Concentrate: 1:4 to 1:8. Typical steep time: 12 to 18 hours.
Common Values
⚠ Watch Out
- •Do not confuse concentrate ratios with ready-to-drink ratios.
- •Measure coffee by weight; volume scoops vary too much.
- •Very fine grinds can clog filters and exaggerate extraction.
- •Keep strained cold brew refrigerated, especially if you batch for several days.
Pro Tips
- →Start with 1:15 for medium roast and adjust from there.
- →Taste the concentrate before choosing your dilution amount.
- →Use filtered water because cold brew has fewer hot aromatics to hide off-flavors.
- →Strain twice if you want a cleaner cup with less sludge.
FAQs
Is 1:15 a good cold brew ratio?
Yes. For many medium roasts, 1:15 lands near ready-to-drink strength and produces a balanced cup without mandatory dilution.
What ratio should I use for concentrate?
A concentrate usually falls between 1:4 and 1:8. Strong cafe-style concentrates often sit near 1:5 or 1:6 so they still have punch after dilution.
Should I measure water by grams or milliliters?
Either is acceptable for planning because 1 milliliter of water weighs almost exactly 1 gram at kitchen temperatures.
Why does my cold brew taste weak even with the right ratio?
Grind may be too coarse, steep time may be too short, or too much liquid may be trapped in the grounds and left behind during straining.
Can I dilute cold brew with milk instead of water?
Yes. The calculator only plans the coffee side of the drink; the final dilution liquid can be water, milk, tonic, or ice melt.
How long should cold brew steep?
Most home batches taste best around 12 to 18 hours in the refrigerator or at cool room temperature, depending on roast and grind.
Does roast level change the ratio?
Usually only slightly. Dark roasts often taste best at a slightly lighter dose, while lighter roasts may need a touch more coffee or a finer grind.