Coffee Ratio Calculator

Divide the weight of your water by the brew ratio and you have the coffee: 500 g of water at 1:16 is 31.25 g of grounds. The ratio is the X in 1 : X, so a bigger number means more water per gram and a milder cup. Most brewers stay between 1:15 and 1:18.

Brewing coffee holds two separate decisions — how strong the cup should be and how much of it you want — and the brew ratio is what keeps them apart. The ratio sets the proportion between water and grounds; the water weight sets the size of the batch. Because the proportion carries the strength, a single division answers both at once: coffee = water ÷ ratio. The default settings are 500 g of water at 1:16, so 500 ÷ 16 = 31.25 g of grounds. Hold the ratio and double the water and the coffee doubles with it — 1000 g at 1:16 is 62.5 g, the same cup in twice the quantity. Move along the other axis instead and the drink itself changes: the same 500 g asks for 33.33 g at 1:15 and 27.78 g at 1:18. What the figure cannot tell you is how any of that will taste. Grind size, water temperature and contact time all shape what is drawn out of the grounds, and none of them enters this division. The 1:15 to 1:18 band that most brewing sits in is a convention to start adjusting from rather than a target, and it belongs to filter-style brewing — espresso runs on a different scale entirely, with far less water meeting each gram.