Grind Size Guide Calculator

What grind actually controls

Grind size sets surface area, which sets extraction speed: finer = faster and more complete extraction, coarser = slower and gentler. Each method's band matches its contact time — espresso's 25 seconds needs fine, a press's 4 minutes needs coarse. The band is physics wearing a coffee hat.

The diagnostic grammar

Sour/thin = under-extracted: finer, hotter, or longer. Bitter/harsh = over-extracted: coarser, cooler, or shorter. Weak = a ratio problem, not grind. This grammar converts taste into a one-variable experiment — the entire skill of dialing in coffee, teachable in one paragraph and mastered over a lifetime of mornings.

The grinder is the upgrade

Grind consistency matters more than grind size: cheap blade grinders produce dust and boulders simultaneously (both extracting wrong), while burr grinders produce uniform particles that extract uniformly. The burr grinder is the highest-leverage purchase in coffee — more than the machine, arguably more than the beans' pedigree.