Spoke · moka pot ratio

Moka pot ratio by pot size

A moka pot fixes its own ratio: the boiler sets the water and the funnel basket sets the coffee. Published capacities and basket doses put most pots near 1 gram of coffee to 10 grams of water. This page lines up the 1, 3, 6, 9 and 12 cup figures, shows where the sources disagree, and the calculator works out the ratio of your own pot.

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

Capacity and dose by pot size

No single source publishes both the water and the coffee for every size. Bialetti’s US sizing guide gives a capacity in ounces; Wikipedia’s table, built from Bialetti product pages, gives millilitres; Bialetti does not state a coffee dose on the pages we opened. The doses come from a US retailer’s Moka Express spec table and a Swiss retailer’s per-cup rule.

Pot	Bialetti US oz → ml	Wikipedia ml	Dose Whole Latte Love	Dose Chronic, 5–7 g/cup	≈ Ratio Bialetti US ÷ WLL dose
1 cup	2 oz → 59 ml	60 ml	not listed	5–7 g	≈1:8.4–1:11.8 with 5–7 g
3 cup	4.4 oz → 130 ml	130 ml	13 g	15–21 g	≈1:10.0
6 cup	9.1 oz → 269 ml	250 ml	26 g	30–42 g	≈1:10.3 (1:9.6 on 250 ml)
9 cup	14.2 oz → 420 ml	410 ml	38 g	45–63 g	≈1:11.1 (1:10.8 on 410 ml)
12 cup	22 oz → 651 ml	595 ml	50 g	not listed	≈1:13.0 (1:11.9 on 595 ml)

Two cautions. First, neither Bialetti’s page nor Wikipedia says whether its figure is the water the boiler takes or the coffee the pot delivers; Whole Latte Love calls its own figures “carafe volume” (4.4, 8.5, 13.5 and 18 oz for the 3 to 12 cup), which run below Bialetti’s numbers from the 6 cup up. Second, the Chronic per-cup rule gives noticeably more coffee than the Whole Latte Love doses. Treat the table as a starting point, then weigh your own pot once.

The formula

water (ml) = fluid ounces × 29.57
water (g) ≈ water (ml) (1 ml of water ≈ 1 g)
ratio = water (g) ÷ coffee (g)
coffee for a 1:10 brew (g) = water (g) ÷ 10

Worked example: a 6 cup pot rated at 9.1 oz holds about 9.1 × 29.57 ≈ 269 g of water. With the 26 g dose from the spec table, 269 ÷ 26 ≈ 10.3, so about 1:10. At an exact 1:10, the same water would want 26.9 g of coffee. Wikipedia describes the typical moka ratio as approximately 1:10 by mass; the general coffee-to-water ratio guide shows how far that is from filter brewing at 1:15–1:18.

Where the sources disagree

Source	Recipe or rule	As a ratio
Wikipedia, Moka pot	“approximately 1:10” coffee to water by mass	1:10
Equator Coffees	3 cup: 15 g to 150 g; 6 cup: 30 g to 300 g	1:10
Compass Coffee	6 cup: 25 g to 275 g heated water	1:11
Kaffeemacher	about 12 g (10–12 g) for a 120 ml pot	≈1:10–1:12
Fulcrum Coffee	18 g to 135 g water, pot size not stated	1:7.5
Whole Latte Love spec table	13 / 26 / 38 / 50 g for the 3 / 6 / 9 / 12 cup	≈1:10–1:13*
Chronic	5–7 g per cup	≈1:6–1:9* 3–9 cup

* Our arithmetic against Bialetti’s US capacities. Note that Equator pours 150 g into a 3 cup pot that Bialetti rates at 4.4 oz (130 ml), so “capacity” is clearly not the same thing as the water a recipe uses.

The roaster recipes agree more than the numbers suggest: Equator, Compass and Kaffeemacher all land between 1:10 and 1:12. The outliers are Fulcrum’s stronger 1:7.5, the Chronic per-cup rule and the 12 cup row of the spec table. Because the basket volume is fixed, the practical way to change strength in a moka pot is grind and fill, not a different ratio; the moka pot guide covers grind and heat.

Collector (upper chamber): the brewed coffee collects here.
Central spout: coffee first appears here and flows into the collector.
Rubber gasket and filter plate (upper filter disc): sit between the basket and the collector and seal the two halves.
Funnel basket: filled level with fine-ground coffee, not tamped; its tube reaches down into the water.
Safety valve: releases pressure if the pot over-pressurizes. Keep the water below it.
Fill line: the etched line, or just below the valve.
Boiler (lower chamber): heated water and vapor pressure push the water up through the coffee, at about 1–2 bar.

Drawn by pourxlab.com for this page. Parts and fill level follow Wikipedia’s moka pot article (source 4), the Fulcrum guide for the spout (source 9) and the Bialetti Brikka instructions and brew guides for the untamped basket (sources 3, 6–11). Not to scale.

Moka ratio calculator

Pot size (fills in published figures)

Water in the boiler (g)

Coffee in the basket (g)

Your ratio1 : 10.3

Coffee for 1:1026.9 g

Dose vs 1:10−3%

Ratio = 269 ÷ 26 ≈ 10.3 · coffee for 1:10 = 269 ÷ 10 = 26.9 g · your dose is 3% less coffee than 1:10 · presets: Bialetti US capacity × 29.57; dose from the Whole Latte Love table

What a moka “cup” means

About 2 oz, not a mug. Bialetti’s US page says moka “cups” are espresso-sized servings of about 2 oz each; its own moka cup holds 60 ml at most. Wikipedia puts a cup at roughly 40–60 ml, and Whole Latte Love lists 1.5 oz per cup. A US 8 fl oz cup is several moka cups; see how much coffee per cup for other cup definitions.
The cup count is a size name. Bialetti’s ounces do not grow in step with the count: the 12 cup is rated at 22 oz but the 18 cup only at 27.3 oz.
Weigh it once. Fill the boiler to your usual line on a scale, then fill the basket level and weigh the coffee. Those two numbers are your pot’s real ratio.

Step by step, by weight

Fill the boiler to the etched line or just below the safety valve. Equator, Fulcrum and Kaffeemacher all say just below; Sweet Maria’s allows “up to the level of the valve or a little over it,” so it is the outlier here. Never block the valve.
Decide on hot or cold water. Equator and Compass preheat the water and Fulcrum uses it at 100 °C to speed brewing; Sweet Maria’s starts with fresh water.
Fill the funnel basket level with fine-ground coffee and do not tamp. Bialetti’s Brikka instructions say never to press coffee into the funnel, and the brew guides agree; Kaffeemacher allows a light press but no tamping. The grind chart has the moka setting.
Wipe the rim, fit the gasket and filter plate, and screw the pot together firmly.
Heat on a low to medium setting. Compass uses medium-low; Bialetti’s Brikka instructions say not to use the highest setting on electric plates. Kaffeemacher’s own step-by-step uses full heat.
Take the pot off the heat when the flow starts to sputter. Whole Latte Love lists about 5 minutes for a 3 cup and 8–10 minutes or more for the 6 to 12 cup; Sweet Maria’s expects about 5 minutes; Compass about 4.

Checklist

Know your pot’s size in cups and in ounces or millilitres
Water weighed once to the fill line, below the safety valve
Basket filled level, not tamped; weigh the dose once
Ratio checked: about 1:10 is typical
Fine grind, coarser than espresso
Low to medium heat
Off the heat at the first sputter
New pot: Bialetti’s Brikka instructions say to discard the first 3 brews

Lab tip: write the boiler water and basket dose of your pot on a strip of tape under the base. The moka pot guide covers how the brewer works and what to do about a bitter cup.