A Free Calculator · Grams, Not Guesses · Updated 2026
How much coffee do you need for cold brew?
Cold brew ratios look deceptively simple until you realize there are two separate
dilution steps: how you steep the concentrate, and how you serve it. Enter your steep
ratio, water weight, and dilution below — the calculator returns your ground coffee,
estimated yield, and serving count. All three formulas are shown in full.
Ground coffee in grams·Diluted yield & cup count·Adjust for concentrate or ready-to-drink
Read this first
This calculator does the arithmetic exactly — but the ratios are taste starting points, not
rules. Coffee density, roast level, grind size, steep time, and water temperature all affect
perceived strength. Grounds absorb water during steeping, so the actual concentrate you pour
off will be slightly less than the steeping water you put in — the yield is labeled
approximate for this reason. Adjust ratios by feel after your first batch.
Set the steep ratio and how much water you're using for the concentrate, then choose how much you'll dilute at serving. Results update as you type.
Steep (concentrate) inputs
parts water : 1 coffee
How many grams of water per 1 gram of coffee in the steep vessel. A value of 5 means 1:5 — a common starting point for concentrate. Lower = stronger. Approximate — adjust to taste.
g
Water added to the steep vessel in grams (1 g ≈ 1 mL). Default 1,000 g fits a standard 32-oz wide-mouth jar.
Serving dilution
parts added : 1 concentrate
How much water or milk you add per part concentrate when serving. 1 means equal parts (1:1). 0 means you drink it straight. Editable — adjust to taste.
Use of ground coffee
Ground coffee needed
Steeping water
Diluted yield (approx.)
Approximate servings
The formulas, in full
Nothing here is a black box. These are the exact calculations the tool runs — the same
arithmetic you could do on paper. The only judgment calls are the ratio inputs you supply,
and those are labeled as starting points throughout.
How each number is derived
1 — Ground coffee needed (from steep ratio and water weight)
coffee_g = water_g ÷ steepRatio
Example: 1000 g ÷ 5 = 200 g coffee
2 — Diluted yield after serving dilution (approximate)
dilutedYield_g = water_g × (1 + dilutionRatio)
Example: 1000 g × (1 + 1) = 2000 g
Note: grounds absorb some water during steeping, so actual
poured concentrate is less than water_g — yield is approximate.
The right ratio depends on whether you're making a concentrate to dilute at serving or
a ready-to-drink brew. All figures below are taste starting points — approximate and
editable. Grind size, water temperature, and steep time shift perceived strength
independently of the ratio.
Style
Steep ratio (water : coffee)
Dilution at serving
Taste profile
Notes (approximate)
Strong concentrate
4:1 – 5:1
1:1 with water or milk
Rich, chocolatey, bold — can taste harsh straight
Most common home method. The calculator defaults here (5:1 steep, 1:1 dilution). Adjust steep ratio in half-steps; stronger than 4:1 often turns bitter.
Lighter concentrate
7:1 – 8:1
1:1 or drink straight
Smoother, brighter, easier to drink without diluting
Good for lighter roasts where acidity is a feature. At 8:1 the concentrate is drinkable on its own for many palates. Set dilution to 0 in the calculator to skip the second step.
Ready-to-drink
10:1 – 12:1
None (0)
Light-bodied, subtle, close to iced coffee strength
Steep time becomes more important at these ratios — under-steep at 10:1 and it tastes thin. Requires more steep vessel space for the same number of servings. Common for cold brew bags and batch systems.
Espresso-style
2:1 – 3:1
3:1 water or milk
Very intense — small pour only
Used as a coffee shot in cocktails, tonics, and specialty drinks rather than as a stand-alone drink. Difficult to filter cleanly without a press or dedicated equipment. Handle in small batches.
All ratios and dilution suggestions are approximate starting points. Taste is the final
judge — a half-ratio shift in either direction is a meaningful change. Coffee variety,
roast level, grind coarseness, water quality, and steep duration each interact with the
ratio to determine the cup in your hand.
Why the ratio matters more than the recipe
Most cold brew failures come from treating a recipe's ratio as fixed rather than as
a calibrated starting point. The ratio controls extraction density — everything else
(time, temperature, grind) modulates it.
The steep ratio and dilution ratio are two separate levers
A 1:5 steep ratio produces a concentrate — not a finished drink. You also decide the
dilution ratio at serving, which is why the calculator asks for both. Changing only the
dilution ratio is the fastest way to adjust perceived strength in an existing batch:
adding less water makes it stronger, more water makes it lighter. The steep ratio is
the slower, batch-level control; the dilution ratio is the fast, glass-level control.
They compound — a 1:4 steep with 1:2 dilution gives a different result than a 1:5 steep
with 1:1 dilution even if both end up at roughly the same total water-to-coffee ratio.
Grams beat volume for coffee every time
A tablespoon of lightly roasted whole beans and a tablespoon of finely ground dark
roast contain very different masses of coffee. Recipes written in volume units are
ambiguous by design. Weighing coffee removes that ambiguity entirely — 200 g is 200 g.
A kitchen scale accurate to 1 gram costs less than a bag of specialty coffee and pays
for itself in avoided bad batches. This calculator uses grams throughout, and water is
close enough to 1 g/mL that the steeping water input doubles as a milliliter count.
Absorption loss is real — plan for it
Coffee grounds absorb roughly twice their weight in water before you filter. With
200 g of coffee steeped in 1,000 g of water, you might absorb 350–400 g of water into
the grounds, leaving roughly 600–650 g of concentrate to pour off — not 1,000 g.
The calculator uses the full steeping water figure as the yield basis (because the
diluted cup after both steps is what matters for planning), but notes that yield is
approximate. If you need a specific number of servings, add 10–20% to your batch size
to account for absorption and filter loss, particularly with a coarse grind.
How to dial in your batch
Cold brew is forgiving to make but slow to iterate — a miscalibrated batch costs you
a full day of steep time. Front-loading a few small decisions eliminates the most
common first-batch failures.
Start with 5:1 steep and 1:1 dilution — then move one lever at a time
The calculator defaults (5:1 steep, 1:1 dilution at serving) are a robust starting
point for most coffee types. On your second batch, move only the steep ratio up or
down by 0.5–1 point, or change the serving dilution. Changing both at once makes
it impossible to know which adjustment moved the cup.
Use a coarse grind — close to French press
Cold water extracts slowly. A coarser grind prevents over-extraction during a
12–24 hour steep and produces a cleaner, less bitter cup. Fine or medium grinds
work but require shorter steep times and produce a silty, harder-to-filter result.
If you're using pre-ground drip coffee, reduce steep time by 3–4 hours and taste.
Steep in the refrigerator for safety and consistency
The refrigerator (34–40°F / 1–4°C) slows extraction and keeps the wet grounds
out of the bacterial growth zone. Steep 12–24 hours cold; 18 hours is a reliable
middle ground for a 5:1 ratio. Room-temperature steeping is faster (8–12 hours)
and produces a different — sometimes harsher — flavor profile, with less margin
for error if you overshoot the time.
Filter thoroughly, then store sealed
A fine mesh filter or a paper coffee filter removes fine particles that turn
bitter over time in the refrigerator. The concentrate keeps well sealed for up
to two weeks cold. Note the batch date — after two weeks the flavor noticeably
degrades even if it still looks and smells fine.
Log your batch — one row per batch is enough
Record steep ratio, water weight, coffee weight, grind size, steep time, and
a one-sentence taste note. Cold brew improves fastest when you have something to
compare against. Two batches in with notes is worth more than ten batches without.
Where to buy
Got your numbers? Here's where to pick up what you need:
The ratio notation and brewing vocabulary that shows up on recipes, bags, and
equipment — in plain English.
Steep ratio
The ratio of water to coffee by weight in the steep vessel. Written as N:1 where N is parts water per 1 part coffee. A 5:1 ratio uses 5 grams of water for every 1 gram of coffee. Lower numbers mean more coffee — a stronger concentrate. All ratios on this page are approximate starting points.
Concentrate
The strong, undiluted liquid filtered from the steep vessel. Most cold brew recipes produce a concentrate at a 4:1–8:1 steep ratio, intended to be diluted at serving with water, milk, or ice. Drinking concentrate straight is common for espresso-style cold brew but unusual at 5:1 ratios.
Dilution ratio
How much water or milk you add to the finished concentrate when serving. A 1:1 dilution adds an equal volume of liquid to the concentrate — one part concentrate, one part diluent. A 0 dilution means no water added: drink the concentrate as-is. The calculator models diluting the entire batch; you can also dilute glass by glass.
Approximate (ratio label)
Every ratio on this page is labeled approximate because no ratio produces the same cup across all coffees, grind sizes, roast levels, and steep times. The ratio is a reproducible starting point — the arithmetic is exact, but the sensory result is not guaranteed by the numbers. Adjust after tasting.
Absorption loss
Coffee grounds absorb roughly 2× their weight in water during steeping. This means the concentrate volume you pour off after filtering is less than the water you poured in — typically 30–40% less for a 5:1 steep. The calculator uses total steeping water in the yield formula and notes the approximation; plan for absorption by making batches slightly larger than your target serving count.
Ready-to-drink (RTD) cold brew
Cold brew steeped at a lower concentration (10:1–12:1) intended to be consumed without further dilution. Commercial bottled cold brew is almost always RTD. RTD brewing requires more steep vessel volume per serving than concentrate-style brewing but skips the serving dilution step entirely.
Steep time
How long the grounds sit in contact with the cold water before filtering. Typically 12–24 hours in the refrigerator, or 8–12 hours at room temperature. Steep time interacts with the ratio: at a given ratio, longer steep time increases extraction intensity similarly to lowering the ratio. This calculator covers quantity math; steep time is a separate variable you control with a timer.
Grind size
For cold brew, coarse grind (similar to French press) is standard. Cold water extracts slowly, so coarser particles prevent over-extraction over a long steep. Fine grind over-extracts and produces bitterness and fine particle sediment. This calculator does not adjust the ratio for grind size — that's a qualitative decision you control at the grinder.
Frequently asked
There is no single best ratio — it depends on whether you're making a concentrate to dilute later or a ready-to-drink brew. For a strong concentrate (the most common method), a 1:4 or 1:5 ratio is typical: 1 gram of coffee per 4–5 grams of water. You dilute the finished concentrate 1:1 with water or milk when serving. For a ready-to-drink cold brew, ratios closer to 1:8 or 1:12 are common. The ratios in the ratio reference table above are starting points — taste is the final judge.
The standard recommendation is 12–24 hours in the refrigerator. A 12-hour steep produces lighter, brighter cold brew; 18–24 hours produces a fuller, more chocolatey result. Room-temperature steeping is faster — 8–12 hours — but can produce a more bitter cup and leaves less margin for timing error. The calculator on this page covers the quantity math; steep time is a separate variable you control with your timer.
Volume measurements for coffee are unreliable because coffee density varies by roast level and grind size. A tablespoon of lightly roasted whole beans and a tablespoon of fine dark-roast grind contain very different masses. Grams remove that ambiguity — 200 g of coffee is 200 g regardless of what you're using. Any kitchen scale accurate to 1 gram is sufficient. Water is close enough to 1 g/mL that the steeping water input in grams doubles as a milliliter count.
Yes — coffee grounds absorb roughly 2× their weight in water during steeping. With 200 g of coffee steeped in 1,000 g of water, you might absorb 350–400 g into the grounds, leaving around 600–650 g of concentrate to pour off — not 1,000 g. The calculator labels the yield as approximate and uses steeping water as the basis because the diluted cup after both steps is what matters for planning. If you need a precise serving count, add 10–20% to your batch size as a buffer for absorption loss.
The dilution ratio describes how much water or milk you add to the finished concentrate at serving time. A 1:1 dilution means equal parts concentrate and diluent — pour 120 mL of concentrate over ice and add 120 mL of water or milk. Set dilution to 0 in the calculator if you drink the concentrate straight. The calculator assumes you dilute the entire batch for yield purposes; in practice you can dilute glass by glass and the per-cup math still holds.
Yes — the ratios hold at any scale. If you want 20 servings instead of roughly 8, increase the steeping water proportionally (about 2,400 g water for a 5:1 steep with 1:1 dilution) and the calculator updates all figures. The only constraint is equipment: a standard 32-oz mason jar holds about 1,000 mL. For larger batches, a dedicated cold brew maker or a food-safe bucket with a filter bag scales more cleanly. The formulas do not change.
Coarse grind — similar to French press. Cold water extracts more slowly than hot water, so a coarser grind prevents over-extraction during a 12–24 hour steep. A fine or medium grind will over-extract and produce a bitter, silty result that is also harder to filter. If you only have pre-ground drip coffee, reduce your steep time by a few hours and taste along the way. This calculator does not adjust the ratio for grind size; that's a qualitative variable you control at the grinder.
The arithmetic is exact for the inputs you enter — the formulas section shows every step. The serving count uses 237 mL (8 oz) as the cup size. Real servings vary: a tall glass over ice holds more like 12 oz, a short glass might be 6 oz, and a mug might be 10–12 oz. The absorption loss from grounds is noted but not deducted — treat the serving count as an upper estimate and expect to pour off slightly fewer cups than shown. Use the result as a planning target, not a guarantee.
Common mistakes with the cold brew calculator
Cold brew has fewer variables than espresso, but the same mistakes come up repeatedly — especially around yield and grind size.
Expecting to pour off all the steeping water as concentrate
Coffee grounds absorb water — roughly 1.5–2× their own weight. That water stays in the grounds when you filter. If you steep 200 g of coffee in 1,000 g of water, you may recover only 600–700 g of concentrate after filtering, not 1,000 g. Plan your steep volume to account for absorption loss. The calculator's notes section flags this; if your yield is consistently lower than expected, increase your steep water by the estimated absorption amount.
Using a medium or fine grind
Cold water extracts slowly. A medium or fine grind left in contact with cold water for 12–24 hours over-extracts, producing a bitter, astringent concentrate full of fine sediment that clogs filters and turns the batch gritty. Use a coarse grind — roughly the same coarseness as French press or coarser. The slow, cold extraction rate is what makes cold brew smooth; a finer grind eliminates that advantage.
Treating steep ratio and serving dilution as one setting
The steep ratio determines how concentrated the cold brew is before dilution. The serving dilution ratio determines how strong your final cup is. These are two independent levers. A batch steeped at 1:4 (one part coffee to four parts water) is very concentrated and meant to be served over ice at 1:1 or 1:2 dilution. Changing the steep ratio without adjusting your dilution ratio produces a finished drink that is either watered down or undrinkably strong.
Steeping at room temperature for as long as you would in the fridge
Room-temperature extraction is significantly faster than cold extraction. The common guideline of 18–24 hours applies to refrigerator temperature (35–40 °F / 2–4 °C). At room temperature (68–72 °F / 20–22 °C), extraction completes in roughly 8–12 hours. Steeping at room temp for 20 hours produces an over-extracted, bitter concentrate. If steeping at room temperature, cap it at about 12 hours and taste at 8.