Coffee Grind Size Calculator

Coffee grind size is one of the most critical variables in brewing great coffee. The grind determines the surface area of coffee exposed to water, which directly controls extraction speed and the balance of flavors in your cup.

The Grind Size Spectrum

Coffee grinders are typically rated on a scale from extra-fine to extra-coarse. The spectrum works like this:

• Extra Fine (like powdered sugar): Turkish coffee only
• Fine (like table salt): Espresso, Moka pot
• Medium-Fine (like fine beach sand): Pour over (V60), AeroPress (fast method)
• Medium (like coarse sand): Drip coffee machines, flat-bottom drippers
• Medium-Coarse (like rough sand): Chemex, AeroPress (inverted)
• Coarse (like sea salt): French press, Percolator
• Extra Coarse (like peppercorns): Cold brew

Why Grind Size Matters

Water extracts coffee compounds at different rates based on particle size. Finely ground coffee has more surface area — water extracts it very quickly. Coarsely ground coffee has less surface area — extraction takes much longer. Matching grind to brew time ensures complete, balanced extraction.

Under-Extraction (too coarse for the method) Results in: sour, weak, watery, acidic coffee

Over-Extraction (too fine for the method) Results in: bitter, harsh, dry coffee

Brew Ratios (coffee to water)

A commonly recommended starting ratio for most methods is:

• 1:15 to 1:17 (coffee:water by weight)
• Example: 20g coffee to 300–340g water

For espresso the ratio is much shorter: 1:2 (20g coffee → 40g espresso output)

Grinder Types

• Blade grinders: Inconsistent, creates a mix of sizes — avoid for quality brewing
• Burr grinders (flat or conical): Uniform grind size — essential for good coffee

This calculator recommends grind settings, brew times, and water temperature for your chosen method.