Burr diameter

The cutting-surface diameter of the burrs — measured across the face of the burr. Common sizes are 40, 50, 58, 64, 75, 83, and 98 mm.

Why it matters — Bigger burrs grind faster (more cutting surface per revolution), run cooler (lower contact pressure per particle), and typically produce a more uniform distribution. But they cost more, take up more space, and need more powerful motors.

Good to know

• For home espresso, 64 mm is the practical sweet spot — café-grade quality without commercial-grade footprint.
• 50 mm burrs are great for hand grinders where physical size matters most; 83 mm and 98 mm are commercial territory.