For most hot filter and immersion coffee, start between 1:16 and 1:18 by mass. In coffee-first notation, 1:16 means 1 g of dry coffee for 16 g of input brew water, so 20 g of coffee uses 320 g of water. This is a starting range, not a rule: taste the result, then change one variable at a time.
An SCA technical overview describes 60 g of coffee per liter of water, equivalent to 1:16.7, as a common ratio for drip and immersion brewing. A newer consumer study found more than one preference pattern, which is one reason to treat the number as a baseline rather than a universal optimum.
Calculate coffee or brew water
The ratio compares dry coffee with input brew water. The arithmetic works in either direction:
Water = coffee × ratio30 g coffee × 16 = 480 g water
Coffee = water ÷ ratio750 g water ÷ 17 = 44.1 g coffee
Milliliters use the kitchen approximation that 1 ml of water is about 1 g. Pure water is 0.99823 g/ml at 20°C in a NIST reference table, so the difference is about two-tenths of one percent at that temperature. US fluid ounces are converted at exactly 29.57353 ml per fluid ounce using the NIST conversion.
For a complete filter recipe, the V60 brewing guide covers grind, bloom, and pouring; this calculator handles the ratio and batch size.
Choose a starting ratio for the brewing job
The useful question is not “Which ratio is perfect?” It is “Which ratio gives this method a sensible first batch?”
| Brewing job | Start here | What the ratio describes | Adjustment boundary |
|---|---|---|---|
| Hot filter | 1:16 to 1:18 | Dry coffee to all input brew water | Grind, pouring, and drawdown still affect extraction |
| Hot immersion | 1:16 to 1:18 | Dry coffee to water added before filtering | Grind, contact time, and separation still matter |
| Cold brew | 1:16 ready to drink; custom for concentrate | Dry coffee to steeping water, before later dilution | A concentrate needs its dilution stated with the brew ratio |
Cold brew is deliberately the least prescriptive row. A 2021 pilot study found no standardized process and documented recipes ranging from 50 to 150 g/L for most survey respondents, with some brewers using even more coffee. The 1:16 figure above is finer.coffee’s ready-to-drink baseline, not a scientific cold-brew optimum.
Change concentration without chasing the wrong variable
For the same amount of water, moving from 1:17 to 1:15 uses more coffee and makes a more concentrated drink. Moving toward 1:18 uses less coffee and makes it lighter.
Concentration and extraction are related, but they are not the same measurement. In full-immersion experiments, strength fell approximately as the water-to-coffee ratio increased, while extraction yield stayed near 21% across the tested equilibrium brews. Drip sensory research also found that strength, extraction yield, and roast can change different attributes (Frost and colleagues, 2020).
That means a ratio change is useful when the whole drink is simply more or less concentrated than wanted. Sourness, bitterness, hollowness, or astringency can instead point to grind, contact time, water temperature, agitation, or pouring. Change the ratio only when concentration is the problem.
Brew water is not the amount in the cup
Ground coffee retains liquid. Filters drain differently, and bypass water, ice, or concentrate dilution can change the final serving. One published drip-coffee mass-balance model uses approximately 2.1 g of retained liquid per gram of dry coffee, but that is a model assumption for its brewing system rather than an exact cross-method constant (Guinard and colleagues, 2023).
For iced coffee or cold-brew concentrate, keep the steeping or brewing water separate from later ice and dilution. The cold brew and iced coffee comparison shows why two recipes with the same starting ratio can finish at different strengths and serving amounts.
If there is no scale
A level 15 ml measuring tablespoon holds roughly 5 g of ground coffee, but about 4 to 6 g is more honest. NIST defines the measuring tablespoon as 15 ml, while a laboratory study found that fine-ground Arabica bulk density varied from 0.28 to 0.39 g/ml across roast levels. Those values translate to about 4.2 to 5.9 g per tablespoon (NIST; Nakilcioğlu-Taş and Ötleş, 2019). Grind size, roast, settling, and filling technique all change the result.
Approximate 1:16 fallback: 1 level tablespoon coffee to 80 ml water; 2 tablespoons to 160 ml; 4 tablespoons to 320 ml.