Espresso Ratio Calculator

1:2 is the common starting point: 1 g of dry coffee to 2 g of espresso, so 18 g in gives 36 g out. The National Coffee Association gives 1:2, and Wikipedia calls ristretto about 1:1, normale 1:2 and lungo 1:4 as a rough guide.

The National Coffee Association says 20 to 30 seconds, and Wikipedia says usually 25 to 30 seconds. A lungo can run longer, up to about a minute. Start the timer when the pump starts and stop when you reach your target weight.

Wikipedia gives 14 to 18 g of ground coffee for a double, and about 14 g in its espresso article. Your basket's maker states its own range, so follow that. The quick buttons for 7 g and 20 g are shortcuts, not sourced figures.

Same coffee, different amounts of water. A ristretto uses about half the water of a normale, and a lungo about double. Wikipedia's rough guide is 1:1, 1:2 and 1:4, and it notes these are relative terms without exact measurements.

Grind finer, keep the dose the same and pull again. The National Coffee Association's rule is that the longer the water touches the coffee, the coarser the grind should be, so a fast shot needs a finer grind. See fixing a sour shot and fixing a weak shot.

Grind coarser and check the dose. See fixing a slow or stalling pour and fixing channeling. For a full routine, read how to dial in espresso.

Weigh it. Wikipedia notes the volume and low density of crema make volume comparisons difficult, and that precise measurement uses the mass of the drink. Put the cup on a scale and tare it.