Coffee Brew Ratio Calculator

The Specialty Coffee Association recommends a ratio of 1:15 to 1:18 (coffee to water by weight) for filter coffee. A 1:16 ratio is widely considered the golden middle ground — that is about 62.5g of coffee per litre of water.

Espresso is a concentrated extraction method that forces hot water through finely-ground coffee under pressure. The 1:2 ratio means for 18g of coffee you use about 36ml of water, producing a small, intense shot. Filter methods use more water for a lighter, larger drink.

Always by weight. A tablespoon of finely-ground coffee weighs more than a tablespoon of coarsely-ground coffee. Using a kitchen scale (ideally accurate to 0.1g) ensures consistency every time you brew.

Finer grinds extract more quickly and produce stronger coffee for the same ratio. Coarser grinds extract less. Match your grind to your method: fine for espresso, medium for pour-over, coarse for French press. Adjust the ratio if you change grind size.

A standard UK mug holds about 250-300ml. A small cup is about 150ml. The calculator defaults to 250ml but you can adjust this to match your preferred cup or mug size.

To make stronger coffee, use a lower ratio (e.g. 1:14 instead of 1:16). For lighter coffee, use a higher ratio (e.g. 1:18). You can also select the custom ratio option to dial in your personal preference.