18 g of dry coffee producing 36 g of liquid espresso is a 1:2 dose-to-yield ratio. Divide beverage mass by dry dose. At a target of 1:2.5, the same 18 g dose has a 45 g target yield. Shot time is another observation; it does not calculate the ratio or extraction percentage.
Calculate and record your own shots
The preloaded numbers are arithmetic examples. They are not site test results or entries in your log. Replace them with measurements, then choose Record this measured shot. The session lists each shot’s dose, beverage yield, seconds, ratio and yield change from the previous entry. Export the CSV before leaving if you want to keep it; reloading the page clears the in-memory session.
Weigh the output you actually collected
La Marzocco’s dose and yield explanation distinguishes dry coffee mass in the portafilter from liquid espresso mass in the cup. Those are the two measurements this calculator uses. It does not use the water tank level, a programmed button time, crema height or the number of labeled shots.
Breville’s dialing-in guide likewise describes using a scale to compare dry input and brewed output. Its recipe examples are starting points for that discussion, not requirements that the notebook enforces for every coffee or basket.
Formulas and example log
actual yield parts = measured beverage grams / dry dose grams
target beverage grams = dry dose grams × target yield parts
difference from target = measured beverage grams − target beverage grams
| Arithmetic example | Dry dose | Beverage yield | Actual ratio | Difference from a 1:2 target |
|---|---|---|---|---|
| A | 18 g | 36 g | 1:2 | 0 g |
| B | 18 g | 40 g | 1:2.2222 | +4 g |
| C | 20 g | 40 g | 1:2 | 0 g |
These rows illustrate the calculation; they are not tasting notes or measured shots. Comparing A and C shows why a larger beverage yield alone does not establish a longer ratio: dose changed too.
The notebook reports changes without diagnosing taste. A faster or slower shot can reflect more than one variable. It supplies no automatic grinder setting, bitterness verdict, crema score, caffeine amount or extraction percentage. The Specialty Coffee Association’s 2018 espresso survey report discusses the measurements and variation in surveyed practice; historical survey averages do not determine what your next shot must be.
Pair the notebook with the right decision
Confirm an exact component using the portafilter and basket source lookup . A calculated ratio does not make a basket mechanically compatible, establish a suitable dose or confirm shower-screen clearance.
Use the brewing-water ratio calculator for drip or immersion input water. For weighing gear, the coffee scale guide discusses the separate equipment choice.
Method and sources
Reviewed October 15, 2026. This is a measurement notebook and reproducible calculation, with no hands-on espresso testing by the site. The session accepts up to 100 reader-recorded shots. CSV contains only their numeric dose, yield, time and ratio values; no account, identifiers, ratings or personal notes are collected.
See Also
If you want to move from general advice into actual product choices, start with Coffee Brew Ratio Calculator, U.S. Coffee Prices: Average Price per Pound Since 1980 and Cost per Cup, and Coffee Maker Buying Guide for Gift Buyers.
For a wider picture after the basics, KitchenAid Cold Brew Coffee Maker Review: Key Things to Know Before You Buy and Best Budget Coffee Machines: Three Routines, Three Honest Picks are the next places to read.