What is the Coffee Brew Ratio Calculator?
The brew ratio is the relationship between the amount of water and the amount of ground coffee you use. It is written as 1:N, meaning 1 gram of coffee for every N grams of water. A common, well-balanced ratio is 1:16. This calculator takes your water amount and your chosen ratio and instantly tells you exactly how many grams of coffee to grind — no guesswork, no weak or bitter brews.
How to use it
Enter the total water you plan to brew with (1 ml of water weighs about 1 g, so 500 ml ≈ 500 g). Then enter your brew ratio as the second number — for filter coffee try 15–17, for a stronger cup use 14, and for lighter results use 18. The calculator divides the water by the ratio and shows the grams of coffee, plus a rough tablespoon estimate for when you don't have a scale.
The formula explained
The math is simple division: $$\text{coffee (g)} = \frac{\text{water (g)}}{\text{ratio}}$$ If you have 500 g of water and want a 1:16 ratio, you need \(500 \div 16 = 31.25\) g of coffee. The smaller the ratio number, the stronger and more concentrated the brew; the larger it is, the more diluted.
Worked example
You want to brew a full carafe with 1000 g of water at a 1:15 ratio. $$\text{Coffee} = 1000 \div 15 = \textbf{66.67 g}$$ That is roughly \(66.67 \div 5.3 \approx 12.6\) tablespoons of ground coffee.
FAQ
What ratio should I use? Start at 1:16 for pour-over and drip. Adjust by ±1 to taste — lower for stronger, higher for lighter.
Do grams and millilitres match? For water, yes — 1 ml weighs essentially 1 g, so you can use them interchangeably here.
Is the tablespoon figure accurate? It is an approximation. Coffee density varies with roast and grind, so a kitchen scale is always more precise.
