What is the best coffee to water ratio?

There is no single best ratio. CupTune's authored starting points run from about 1:15 to 1:17 for filter methods and 1:2 for espresso beverage ratio, and the right one for you is whichever you can repeat and then adjust from.

Is a 1:16 ratio the same for espresso?

No. Filter ratios use brew-water mass; espresso conventionally uses beverage mass out divided by dose in. A 1:2 espresso and a 1:16 filter brew are measured differently and cannot be compared directly.

How much coffee do I need for one litre of water?

At 1:16 you need 62.5 g of coffee for 1000 g of water. At 1:15 it is 66.7 g and at 1:17 it is 58.8 g. The calculator derives this from whichever value you edit.

Do I need to weigh water, or can I measure volume?

Volume is fine for water: one millilitre of water is close enough to one gram for brewing. Coffee is the measurement that genuinely needs a scale, because its density changes with roast and grind.

The number everything else hangs off

Coffee to water ratio, explained properly

A brew ratio is two masses. Once that is clear, most of the confusion in coffee recipes turns out to be one word doing two jobs.

The same dose of coffee meets very different amounts of water depending on the method. Espresso is drawn on the beverage ratio, which is why it sits so far left.

Ratio is mass, not volume

Brew ratio here means brew-water mass divided by dry-coffee mass. Espresso beverage ratio instead uses beverage mass divided by dry dose. Those are two different measurements, and the Specialty Coffee Association on brew and beverage ratios keeps them apart for a reason: a 1:2 espresso and a 1:16 filter are not two points on one scale.

Write it as 1 : x, where x is how many grams of water each gram of coffee gets. A 20 g dose at 1:16 takes 320 g of water. That is the entire arithmetic, and CupTune's ratio calculator does nothing more clever than that.

Why grams beat millilitres and scoops

Water is close enough to 1 g per ml that swapping the two costs you little. Coffee is not: a scoop of light-roast beans and a scoop of dark-roast beans differ in mass, because roasting drives off water and expands the bean. A recipe in scoops silently changes strength when you change bag. This is the entire argument for a scale, and it is covered properly in why a scoop cannot be a recipe.

Picking a starting ratio

Start from the method, not from a number you liked once. The ratio chart lists CupTune's authored starting points for each method and scales any of them to your dose. They are starting points: a place to begin a comparison, not a target to hit.

Then change one thing. If the cup is weak, a shorter ratio raises strength directly without touching the grinder. If it is sour or harsh, that is likely extraction rather than strength, and the dial-in guide separates those two cases before suggesting a move.

The mistake almost everyone makes once

Brew water is not beverage yield. Ground coffee keeps some of the water you pour on it: roughly two grams per gram of dry coffee for a filter brew, which is why 320 g of water gives you noticeably less than 320 g in the cup. CupTune treats that two-gram figure as an editable planning assumption rather than a property of your coffee, because it is not one.

What a ratio cannot tell you

Ratio fixes the proportion, not the extraction. The same 1:16 can be under-extracted or over-extracted depending on grind, temperature, time and agitation, and current SCA Brewing Chart research shows that sensory attributes do not sort neatly into one universal correct zone anyway. A ratio makes a brew repeatable. It does not make it good.