Tool
Extraction yield calculator
Dose, beverage weight and TDS give the proportion of the coffee that actually dissolved — which taste alone frequently cannot distinguish from simple dilution.
Extraction yield
19.8%
The drink is in a fairly ordinary range at 1.35% dissolved solids, and 19.8% of the coffee dissolved. Those are separate things: concentration is set by the ratio, and extraction by grind, time and agitation.
Within the range most filter brewing guidance treats as typical. That is a convention derived from tasting panels, not a law: a brew inside it can still taste bad, and one outside it can be excellent.
How this was worked out
Dissolved coffee = beverage weight × TDS
440 × 1.35% = 5.94 g
Extraction yield = dissolved coffee ÷ dose
5.94 ÷ 30 = 19.8%
The percentage of the dry coffee that ended up dissolved in the cup. It says nothing about whether the coffee is good.
An evidence-based range, not a measurement
How it works
Beverage weight multiplied by TDS gives the mass of dissolved coffee in the cup; divided by the dose, that is the extraction yield. The tool also checks the result for plausibility, because the commonest input error — using brew water instead of beverage weight — produces a number that looks reasonable and is a quarter too high.
What the inputs mean
- Beverage weight
- The mass of liquid in the cup, weighed. Not the water poured in: a coffee bed retains roughly twice its own weight, so the two differ substantially.
- TDS
- Total dissolved solids, as a percentage, from a refractometer. It measures concentration — how strong the drink is — and on its own says nothing about extraction.
- Extraction yield
- The proportion of the dry coffee that dissolved. A weak drink can have a normal yield (it is simply dilute) or a low one (it is under-extracted), and those need opposite fixes.
Worked examples
A 30 g pour-over
- Dose 30 g
- Beverage 440 g
- TDS 1.35%
Result: 5.94 g of coffee dissolved, which is a 19.8% yield — inside the range filter guidance treats as typical.
The same brew, measured against brew water by mistake
- Dose 30 g
- Beverage 500 g entered
- TDS 1.35%
Result: 22.5% — apparently over-extracted, and wrong by the water the grounds kept.
This is why the tool checks plausibility rather than simply returning the arithmetic.
Common mistakes
Entering brew water instead of beverage weight
The grounds retain a large share of the water, so the figure comes out roughly a quarter too high — enough to turn an under-extracted brew into an apparently ideal one.
Treating a number inside the band as a good cup
The band is a convention derived from panel preference. Plenty of coffee inside it tastes unpleasant and plenty outside it is excellent.
Comparing an espresso reading against a filter target
They are different measurements on different beverages with different reliability. Compare espresso readings only against your own other espresso readings.
What the result does not mean
- Extraction yield does not measure quality. It measures how much of the coffee dissolved, which explains what you tasted rather than judging it.
- This is not a laboratory measurement. A handheld refractometer, an uncooled sample and an uncalibrated instrument each move the figure more than most people expect.
What this does not account for
- Assumes the refractometer was calibrated and the sample cooled to its stated range. Both are common sources of inconsistent readings.
- Filter bands come from widely used brewing guidance derived from tasting panels, not from a law of nature.
- Espresso is deliberately not banded: its readings are the least reliable a refractometer makes, and published ranges for it are contested.