What Is the Right Pour Over Ratio for One Cup?

What to take away

Start at 1:16 by weight: 1 gram of coffee to 16 grams of water. That is 22 g of coffee and 355 g of water for a 12-oz mug.
Weigh both. A US cup is 8 fl oz, but most mugs hold 10 to 14 fl oz, so cup markings on a carafe mislead.
Grind medium, between table salt and coarse sand, and expect to adjust it before you adjust the ratio.
If the cup tastes thin and sour, tighten the ratio to 1:15. If it tastes bitter and drying, open it to 1:17.

Why cups and grams disagree

The word cup causes most of the trouble. A US customary cup is 8 fluid ounces, or about 237 milliliters. A coffee mug in a normal kitchen cabinet often holds 12 ounces, and a travel mug can hold 16 or more. Recipes written in cups assume the first number, and drinkers pour into the second.

Grams remove the ambiguity because they measure mass, not volume. Water at room temperature weighs close to 1 gram per milliliter, so 355 g of water is 355 ml, or 12 fl oz. Coffee does not follow that rule, since a scoop of grounds traps air. A level tablespoon of medium-ground coffee weighs roughly 5 to 7 g depending on roast and grind, which is a wide enough spread to change the cup.

The fix is a scale that reads to 0.1 g and costs less than a mid-range grinder. A compact model with a built-in timer helps, since you can watch weight and time on one display. The kitchen scale reference explains the accuracy features that matter and the ones that do not.

What you need before starting

A burr grinder. Blade grinders produce uneven particles, and uneven particles brew unevenly.
A scale reading to 0.1 g, with a 1 kg capacity or better.
A dripper and a paper filter sized to it.
A kettle, ideally with a narrow spout for control.
Fresh water and a mug you have measured once.

Measure your mug before anything else. Fill it with water, pour that water onto the scale, and note the number. That number, not the word cup, sets your batch size.

The sequence

Weigh 22 g of whole beans, then grind them medium. Set the dripper on the scale, add the filter, and rinse it with hot water. Dump the rinse water.
Add the grounds and tare the scale to zero. Start a timer and pour 60 g of water at about 200 F. This is the bloom, and it should bubble and settle for 30 to 45 seconds.
Pour in slow circles to 160 g by 0:45, then pause briefly.
Continue to 250 g by 1:30, keeping the water level below the rim of the dripper.
Finish at 355 g by 2:15 and let the bed drain. Total brew time should land between 2:30 and 3:30.

Where judgement replaces the recipe

The ratio is a starting point, not a law. Roast level shifts the target. Dark roasts dissolve faster, so they often taste better slightly weaker, near 1:17. Light roasts need more contact, so 1:15 is common. Decaffeinated beans behave differently again, and the decaffeination process explains why those beans can drain faster and taste flatter at the same ratio.

Grind is the other dial. If the brew finishes in under 2 minutes, the grind is too coarse and the water runs past the grounds before extracting much. If it stalls past 4 minutes, the grind is too fine. Change one variable at a time, and change grind before ratio.

Water matters too. Hard water leaves scale and mutes flavor, and the water hardness reference covers how that is measured. If your tap water tastes flat, filtered water is the cheapest upgrade you can make.

How to tell it is right

Taste is the test, but there is a measurable one beside it. A well-extracted single cup finishes draining between 2:30 and 3:30, leaves a flat bed of grounds with no crater, and tastes sweet with a clean finish. A crater in the middle means the pour was too aggressive.

If the bed looks like mud and the cup dries your mouth, the grind is too fine. If the bed looks like gravel and the cup tastes like tea, the grind is too coarse.

Extraction yield gives a number if you want one. Refractometers measure total dissolved solids, and a typical target is 1.15 to 1.35 percent TDS for filter coffee, which works out near 18 to 22 percent extraction. That range is illustrative, not a rule, and taste still decides.

Fixing it when it is not

The common failure is a sour, thin cup that drains too fast. That is under-extraction, and the named recovery is to grind finer by one or two clicks and keep the ratio the same. Brew it again and taste. If it is still sour, tighten the ratio to 1:15.

The opposite failure, a bitter and drying cup that drains slowly, calls for a coarser grind. Do not fix bitterness by adding water alone. That dilutes the cup without removing the compounds causing the problem.

A single cup magnifies every error because there is less volume to hide behind. The brewing mistakes list covers the fixes worth trying before you blame the beans, and it pairs well with this method once your ratio is stable.

Example of a 12-oz mug

Item	Amount
Mug capacity	355 ml (12 fl oz)
Coffee	22 g
Water	355 g
Bloom water	60 g
Target brew time	2:30 to 3:30

Scale the table by mug size. A 10-oz mug takes about 18 g of coffee and 295 g of water. A 16-oz travel mug takes about 28 g and 450 g. Keep the ratio fixed and change both numbers together.

Common questions

How much coffee for one cup pour over? About 22 g of coffee for a 12-oz mug at 1:16. If you use tablespoons, that is roughly 3 to 4 level scoops, but weigh it once to see how far off your scoop runs.

Does the ratio change for iced pour over? Yes. Brew stronger, near 1:12, and pour the hot concentrate over ice. The melting ice supplies the missing water, so the final cup lands near your normal strength.

Can I use a measuring cup instead of a scale? You can, and the cup will vary by several grams of coffee each time. A scale costs less than a bag of good beans and removes that variance for good.

Why does my cup taste different every morning? Grind setting drift, stale beans, and pour speed are the usual causes. Weigh the dose, check the grind, and time the brew. The pour over stage guide shows what each phase should look like when the brew is on track.