Spoke · AeroPress ratio

AeroPress ratio

There is no single AeroPress ratio, because there are two ways to use one. Either brew at drinking strength, about 1 gram of coffee to 11–14 grams of water, or brew a strong concentrate and dilute it afterwards. This page lines up the published recipes, shows how the dilution math adds up, and the calculator does it for your own dose.

Updated 2026-10-22 · sources listed at the end · ratios marked ≈ are our arithmetic from the sources’ figures

Full-strength recipes: water in the chamber only

These recipes put all the water in the chamber and press straight into the cup. The ratio is simply water ÷ coffee.

Source	Coffee	Water	Ratio	Notes
AeroPress instructions (Original / Clear)	16–18 g	to the “4”	not stated	185 °F (85 °C), stir 3 s, wait 60 s (30 s with a medium-fine home grind); no grams of water given
Counter Culture	18 g	200 g	1:11	Inverted, 200 °F, steep to 1:30; “one, 7 oz cup”
Stumptown	17 g	220 g	1:13	“to about the No. 4 mark”, about 205 °F; dilute with hot water to taste
PT’s Coffee	18 g	250 g	1:14	Filled in three steps to the 1, 2 and 3 marks; 195–200 °F
WAC 2021 champion (Tuomas Merikanto, Finland)	18 g	200 g	≈1:11.1	Inverted, 80 °C; no water added after pressing
Wikipedia, competition parameters	14–20 g	≈200–230 ml	≈1:10–1:16	80–92 °C, 30–60 s steep

So the full-strength recipes cluster around 1:11 to 1:14, a little stronger than the 1:15–1:18 common for pour-over (see the coffee-to-water ratio guide). The maker’s own grams page suggests 14–15 g “per cup” as a starting point and does not tie it to a water weight.

Concentrate + dilution: the two-ratio recipes

The other approach uses little water in the chamber, presses a concentrate and then adds water, either in the carafe beforehand (“bypass”) or afterwards. AeroPress’s own XL Americano does this: 30 g of coffee, 100 g of water in the chamber, then 300 g of water in the carafe. In the chamber that is ≈1:3.3; in the cup, counting all 400 g of water, it is ≈1:13.3. Its “AeroPress for two” page works the same way: three rounded scoops, water to the 3, then hot water to 8 oz (237 ml) per mug, for up to three mugs. At AeroPress’s 14 g per rounded scoop that is ≈42 g of coffee for ≈711 ml of drink, about 1:17 (our arithmetic).

Recent World AeroPress Championship (WAC) winners nearly all brew this way. All figures below are from the championship’s recipe page; the ratios are ours.

Year	Champion	Coffee	Chamber water	≈ Brew ratio	Pressed out, then added	≈ Final
2025	Némo Pop, Australia	18 g	100 g, 84 °C	1:5.6	70 g bypass water at 50 °C put in the carafe before brewing	1:9.4 total water
2024	George Stanica, Romania	18 g	100 g, 96 °C	1:5.6	≈76–79 g out; warm water to 130–135 g, then 20–30 g room-temperature water	1:8.3–1:9.2 150–165 g drink
2023	Tay Wipvasutt, Thailand	16 + 2 g	100 g, 89 °C	1:5.6	≈75 g out; room-temperature water to 115 g, hot water to ≈155 g	1:8.6 155 g drink
2022	Jibbi Little, Australia	18 g	94 ml, 90 °C*	1:5.2	58–64 g out; 90 °C water to 150 g	1:8.3 150 g drink
2019	Wendelien van Bunnik, Netherlands	30 g	100 g, 92 °C	1:3.3	Add 100 g water (“I ended up with 120g dilution”)	1:6.7–1:7.3 total water
2018	Carolina Garay, USA	34.9 g	100 g, 85 °C	1:2.9	60 g water at 85 °C + 40 g at room temperature	1:5.7 total water
2017	Paulina Miczka, England	35 g	150 g, 84 °C	1:4.3	≈90 ml concentrate at 4.5% TDS; add 160–200 g hot water	1:8.9–1:10 total water*
2016	Filip Kucharczyk, Poland	35 g	150 g, 81 °C	1:4.3	Add 100–120 g water to taste	1:7.1–1:7.7 total water

* See “Where the sources disagree” below. “Total water” = chamber water plus added water, ÷ coffee. Where a recipe states a final drink weight, the ratio is drink ÷ coffee instead. 2023’s brew ratio uses the full 18 g.

Two patterns stand out. The chamber ratio is very strong, about 1:3 to 1:6, and the finished drinks land around 1:6 to 1:10, stronger than the full-strength recipes above. The championship recipes are tuned for one competition coffee; the AeroPress guide has the full table back to 2009.

The formula

brew ratio = chamber water (g) ÷ coffee (g)
total-water ratio = (chamber water + added water) ÷ coffee
added water for a target = coffee × target − chamber water
concentrate out ≈ chamber water − coffee × R
drink ≈ concentrate out + added water
water (ml) = fluid ounces × 29.57 (1 ml of water ≈ 1 g)

R is the water the grounds (and the brewer) hold back per gram of coffee. No source publishes it, but four championship recipes give both the water in and the concentrate out, so it can be worked out (our arithmetic):

2022: 94 − (58 to 64) = 30–36 g held back from 18 g, so R ≈ 1.7–2.0.
2023: 100 − 75 = 25 g from 18 g, R ≈ 1.4.
2024: 100 − (76 to 79) = 21–24 g from 18 g, R ≈ 1.2–1.3.
2017: 150 g in, “about 90ml” out from 35 g, R ≈ 1.7 (treating 1 ml as 1 g).

That is a range of about 1.2 to 2.0; the calculator starts at 1.6, the middle of it. Worked example with the XL Americano: 30 g and 100 g gives ≈1:3.3 in the chamber; for a 1:15 cup instead of its ≈1:13.3, add 30 × 15 − 100 = 350 g of water rather than 300 g. With R = 1.6 the concentrate is about 100 − 48 = 52 g, and the drink about 52 + 350 = 402 g.

Chamber water: 100 g of hot water. With little water, the chamber ratio is strong (≈1:5.6 here).
Coffee: 18 g in total (the 2023 recipe adds 16 g, then 2 g).
Concentrate: about 75 g after pressing.
Held back: the rest stays in the grounds and brewer, ≈25 g here (our arithmetic: 100 − 75).
First addition: room-temperature water to 115 g.
Second addition: hot water to about 155 g, ≈1:8.6 drink ÷ coffee.

Drawn by pourxlab.com for this page. Weights follow Tay Wipvasutt’s 2023 champion recipe on the World AeroPress Championship recipe page (source 8); the held-back amount and ratios are our arithmetic. Not to scale.

AeroPress ratio + dilution calculator

Start from a published recipe

Coffee (g)

Water in the chamber (g)

Water added after / bypass (g)

Target total ratio, 1 :

R, held back per g coffee

Brewer (listed capacity)

Brew ratio1 : 3.3

Total-water ratio1 : 13.3

Added water for target350 g

≈ Concentrate52 g

≈ Drink352 g

Brew ratio = 100 ÷ 30 ≈ 3.3 · total = (100 + 300) ÷ 30 ≈ 13.3 · for 1:15 add 30 × 15 − 100 = 350 g · concentrate ≈ 100 − 30 × 1.6 = 52 g · drink ≈ 52 + 300 = 352 g · listed capacity 20 oz ≈ 591 ml

Where the sources disagree

Question	What the sources say
What the numbers on the chamber hold	AeroPress’s instructions give marks, not grams, and its help page on water levels gives no volumes. Stumptown puts 220 g at “about the No. 4 mark”; PT’s Coffee puts about 250 g at the 3 (83 g at the 1, 167 g at the 2). One owner’s published measurement of the smaller Go chamber found about 85, 140 and 200 ml at its 1, 2 and 3.
How much a scoop holds	AeroPress’s grams page: level scoop 11.5 g, heaping scoop 14 g. Its espresso-style recipe calls 19 g a “rounded scoop”; its instructions pair “1 heaping Scoop” with 16–18 g.
Water temperature	AeroPress instructions 185 °F (85 °C); Wikipedia 80 °C for dark and 85 °C for lighter roasts; XL Americano 175 °F (79 °C); Counter Culture 200 °F; PT’s 195–200 °F; Stumptown about 205 °F; champions 80–96 °C.
2022 champion’s water	90 °C on the championship site; 92 °C (198 °F) in the set-up on AeroPress’s copy of the recipe.
2017 champion’s total water	The header says 370 g; the steps add up to 310–350 g (150 g + 160–200 g). The table above uses the steps.
Dilute or not	The maker’s basic instructions add no water after pressing; its “for two” and XL Americano recipes do. Counter Culture adds none; Stumptown says dilute to taste.

Step by step: brewing to a ratio

Pick a style. Full strength: about 1:11–1:14 in the chamber, nothing added. Concentrate: about 1:3–1:6 in the chamber, then dilute.
Check the size. AeroPress lists 10 oz (≈296 ml) for the Original and Clear, 8 oz (≈237 ml) for the Go and 20 oz (≈591 ml) for the XL. PT’s 250 g recipe already uses most of a 10 oz brewer before the coffee is counted (our arithmetic); for more than one cup, AeroPress’s own “for two” recipe brews a concentrate and dilutes it.
Weigh coffee and water. The marks differ between guides, so a scale is the reliable way; see coffee scales explained.
Steep and press. AeroPress’s instructions wait 60 seconds and press gently until the hiss; Counter Culture steeps to 1:30.
Dilute by weight. Put the carafe on the scale and add water to the drink weight or total ratio you want; the calculator gives the grams.
Change one thing at a time. Ratio first, then grind (grind chart) and temperature (water temperature).

Checklist

Coffee weighed (14–18 g is the usual single-cup range above)
Full strength: water at about 11–14 × the coffee
Concentrate: chamber water at 3–6 × the coffee, the rest added after
Total water (or drink weight) checked against your target
Water inside the listed capacity of your brewer
Temperature chosen: 175–205 °F across the sources
Press gently; stop at the hiss

Lab tip: write two numbers in your log, chamber water and total water. “18 g, 100 → 150 g” describes a concentrate recipe completely; a single ratio does not. The AeroPress was invented by Alan Adler and unveiled in November 2005; the AeroPress guide covers upright vs inverted brewing and the full championship archive.