Clara Bennett, CQI Q Grader, SCA Roaster · Last reviewed June 29, 2026

Cold Brew Coffee Ratio Calculator

Tell it your jar size — or the coffee you have on hand — and get the exact grams of coffee to weigh, the ratio, how much concentrate you'll actually pour off, and how many glasses it makes after you dilute. Concentrate or ready-to-drink, your strength, your numbers. No signup, no ads.

Cold brew coffee ratio calculator: choose concentrate or ready-to-drink, pick a strength, enter your jar size or the coffee you have, and see grams of coffee, the ratio, your yield after dilution, and how many servings it makes.

Brew strong, then dilute to taste — the flexible house method.

Or pick a common jar size:

Enter your jar size (or the coffee you have) and the calculator shows the grams of coffee, the ratio, your yield after dilution, and how many servings it makes.

Ratios and yield are a starting point, not gospel. Grind, roast, and steep time all move the dial, and spent grounds retain roughly twice their weight in water — so the finished yield and serving counts are estimates. Weigh your coffee for repeatable cups. Reviewed by Clara Bennett, CQI Q Grader.

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How to use this calculator

  1. Pick concentrate or ready-to-drink. Concentrate (the default) is brewed strong and diluted when you serve — the flexible house method. Ready-to-drink is brewed at sipping strength so you pour it straight over ice. They use very different ratios, which is exactly why a single "cold brew ratio" number on a blog post is misleading.
  2. Choose a strength. Mild, Balanced, or Strong nudges the ratio. Balanced concentrate is the house 1:4.5; Balanced ready-to-drink is 1:10. Want a number that isn't on the menu? Tap Custom ratio and type your own.
  3. Set your dilution (concentrate only). Classic 1:1 is the standard pour; go Strong (2:1) for a bolder glass, Light (1:2) to stretch it, or Straight to build an iced latte over milk. The serving count updates as you change it.
  4. Enter your batch. Switch Brew by to "Water (jar size)" and type your jar volume — or tap a common jar chip — and it tells you the coffee. Flip to "Coffee I have" to work the other way from the beans left in the bag. Units toggle between grams, millilitres, and fluid ounces.
  5. Read your recipe. The card shows grams of coffee to weigh, the steep water, the ratio, and — the part no other tool gives you — your concentrate yield, the finished volume after dilution, and how many 12 oz servings that is. It recalculates instantly; there's no "calculate" button.
  6. Save it. Copy the recipe, share a link that reopens the calculator with your exact settings, or download a branded brew card PDF to tape to the fridge.

Why this cold brew calculator is different

Search "cold brew coffee ratio" and you'll get a wall of blog posts, each stating a single number — and they don't agree. Counter Culture brews 1:8 and dilutes, Sample Coffee says 1:12 ready-to-drink, Serious Eats starts at roughly 1:5, and our own cold brew guide runs a 1:4.5 concentrate. They're all right, for the cup they're after. There's exactly one calculator on page one, and it stops at "ratio in, coffee out." Here's what this tool does that none of them can:

  • It models the whole cold brew arc, not just the steep. Cold brew is brew-strong-then-dilute. This tool takes you from steep ratio → concentrate yield → diluted volume → number of glasses. A static "1:4" tells you nothing about how many drinks you're actually making.
  • It tells you your real yield. Spent grounds soak up roughly twice their dry weight in water and keep it, so you pour off less than you poured in. This is the math everyone does wrong by assuming the jar's worth of water becomes a jar's worth of coffee. We subtract the absorption and show the honest number.
  • It works in both directions. Size by your jar or by the coffee you have left — handy when you're scraping the bottom of a bag and want to know how big a batch it'll make.
  • It respects strength as a dial. Concentrate vs ready-to-drink, three strengths, four dilutions, and a custom ratio for the picky brewer — every combination is a sane, sourced cold brew, not a number pulled from the air.
  • It's shareable and embeddable. Copy a link, export a PDF brew card, or drop the whole calculator onto your own coffee blog with the free embed snippet at the bottom — attribution included.

How it works (the math behind the jar)

A coffee "ratio" is grams of coffee to grams of water, written 1:X. Because water weighs almost exactly 1 gram per millilitre, the core of it is one division. Cold brew adds two steps that hot brewing doesn't — absorption and dilution: 

water_g     = jar_volume x density        (1 mL water = 1 g; 1 fl oz = 29.57 g)
coffee_g    = water_g / ratio              (ratio = the X in 1:X)
absorbed_g  = coffee_g x 2                 (grounds keep ~2 g water per g coffee)
yield_g     = water_g - absorbed_g         (what you actually pour off)
finished_g  = yield_g x (1 + dilution)     (e.g. 1:1 dilution doubles it)
servings    = finished_g / 355             (one 12 fl oz glass = ~355 g)

The part the internet fights about is the ratio itself. This calculator anchors each style to widely-cited standards and to Clara's published method: concentrate at 1:4 to 1:5 (house 1:4.5, the same as Preppy Kitchen's 1:4 and the middle of Counter Culture's range) and ready-to-drink at 1:8 to 1:12 (Sample Coffee's 1:12, Five Star's 85 g per litre). The absorption factor of two grams of water per gram of grounds is the standard liquid-retention figure for brewed coffee; it's why your finished concentrate is noticeably less than the water you started with. The grams are weight, not volume, on purpose — a scoop of dark roast can weigh a third less than the same scoop of light roast, which is exactly why cold brew recipes that work in cups quietly drift in strength.

Three batches from the calculator

A quart jar of classic concentrate

Fill a 32 oz (946 mL) mason jar, leave it on Concentrate / Strong (1:4), and the calculator returns about 237 g of coffee. Steep 14 hours, strain twice, and you pour off roughly 473 g of concentrate — which, cut 1:1 with water or milk, becomes about 946 g of cold brew, or two and a half tall glasses. That's a week of afternoon coffee from one jar.

Sizing a batch from the bag

Switch Brew by to "Coffee I have," type in the 100 g left in your bag on Concentrate / Balanced (1:4.5), and you get a 450 g water target. After absorption that's about 250 g of concentrate — perfect for a few iced lattes poured straight over milk, with no water added at all.

A ready-to-drink pitcher for guests

Set the style to Ready-to-drink / Balanced (1:10) and enter 1,000 g of water, and the calculator returns 100 g of coffee and a finished yield of about 800 g — roughly two and a half glasses you can pour straight over ice without diluting. Same engine, completely different recipe, because cold brew strength is the ratio, not the steep time.

Frequently asked questions

What is the best coffee-to-water ratio for cold brew?

It depends on whether you're making concentrate or a ready-to-drink batch. For a concentrate you'll dilute before drinking, use 1:4 to 1:5 — Balanced here is 1:4.5, which is my house standard because it's the most flexible. For a ready-to-drink batch you pour straight over ice, go weaker at 1:8 to 1:12. Work by weight, not scoops: ground coffee density varies enough between roasts that volume measurements silently change your strength batch to batch.

How much coffee for a quart (32 oz) of cold brew?

A 32 oz jar holds about 946 g of water. At a 1:8 ready-to-drink ratio that's roughly 118 g of coffee; as a 1:4.5 concentrate it's about 210 g, which you'll then dilute into far more than a quart of finished drink. Enter your jar size above and the calculator does the division — and tells you how many glasses the batch actually makes after dilution.

How long should cold brew steep?

Twelve to sixteen hours at room temperature, or sixteen to twenty in the fridge since cold slows extraction. Here's the myth-buster: caffeine extraction largely plateaus around seven hours, so steeping for 24 hours barely adds strength — it mostly adds bitterness. The lever that controls strength is the ratio, not marathon steep times. Use more coffee for a stronger batch, don't just wait longer. Our full cold brew guide covers the extraction science in depth.

Why is my finished cold brew less than the water I added?

Because the spent grounds keep a lot of it. Coffee grounds retain roughly twice their dry weight in water, so a batch with 100 g of coffee holds back around 200 g of liquid you'll never pour off (and you should never squeeze the grounds to reclaim it — that forces bitter silt into the cup). This calculator subtracts that absorption so the yield and serving counts are honest, which is the single thing static ratio charts get wrong.

Is cold brew ratio the same as iced coffee or hot brew?

No. Iced coffee is hot-brewed coffee poured over ice, so it uses hot-brew ratios around 1:15 to 1:17. Cold brew uses a much tighter ratio (1:4 to 1:12) because cold water extracts slowly and, for concentrate, because you're going to dilute it. If you also brew hot, our coffee ratio calculator handles French press, pour over, drip, AeroPress, and Moka pot.

Cold brew is the most equipment-tolerant method in coffee, but three things turn a number into a repeatable batch:

  • A burr grinder for an even, coarse grind — blade grinders make dust that passes through the filter and over-extracts into a muddy, bitter cup. The recommended-gear cards under your result point to the burr grinder Clara reaches for.
  • A scale so you actually hit the ratio above. Cold brew lives or dies by its ratio, and ratios only hold by weight.
  • The right brewer for your batch. A wide-mouth jar maker is plenty for a quart; if you're brewing a half-gallon every week, a bigger kit saves you the hassle. Full walk-through in our how to make cold brew guide.

Sources & methodology

Ratios are conventions and yield is an estimate (grounds retention varies with grind) — reviewed by Clara Bennett, CQI Q Grader. About Clara · Last reviewed June 29, 2026.

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