Free coffee calculator
Extraction yield and TDS calculator
TDS, or total dissolved solids, is the share of the drink that is dissolved coffee. A refractometer measures it. Extraction yield is the share of the dry coffee that ended up in the cup.
Enter the dose, the weight of the finished drink, and the TDS reading. The calculator gives the extraction yield and places the brew on a control chart with strength on one axis and extraction on the other.
Try it: extraction yield
Turn a refractometer reading into extraction
Extraction yield
19.5 %
In the common 18 to 22 percent range. If it tastes good, keep the recipe.
How it works
Extraction yield (%) = TDS (%) × beverage weight (g) ÷ coffee dose (g).
For 20 g of coffee, 300 g in the cup, and a reading of 1.3 % TDS: 1.3 × 300 ÷ 20 = 19.5 % extraction. Weigh the drink itself, not the water you poured, because the grounds hold some water back.
The shaded zone is the traditional filter coffee target of 18 to 22 % extraction at 1.15 to 1.35 % TDS. It is a useful reference rather than a rule. A brew outside it can still taste good, and taste should decide.