Coffee Brew Ratio Calculator

How Brew Ratios Shape Flavor

Coffee brewing is a balance of concentration and extraction. The brew ratio—coffee to water—defines the strength of the final cup. A lower ratio like 1:12 produces a stronger, more concentrated drink, while a higher ratio like 1:17 creates a lighter, brighter cup. Most pour-over and drip brews fall between 1:15 and 1:17, while AeroPress and espresso-style brews tend to be stronger.

This calculator starts from the ratio associated with your brew method and computes the missing amount. If you know how much water you want, it determines how much coffee to grind. If you already have a measured dose of coffee, it tells you how much water to use. Because water density is close to 1 g/ml, you can treat grams and milliliters interchangeably for brewing. The same is true for ounces and fluid ounces in the context of coffee recipes.

Ratio is only one part of the equation. Grind size, brew time, and temperature influence extraction. A coarse grind with a long steep (French press) can use a higher ratio without tasting weak, while a finer grind can extract more quickly and may taste bitter if the ratio is too low. Use the ratio as your baseline, then adjust to taste. If your cup tastes sour, try a slightly lower ratio or a finer grind. If it tastes bitter or heavy, increase the ratio or coarsen the grind.

Consistency is the biggest win. By measuring both coffee and water, you can repeat great cups and share recipes with accuracy. Once you find a ratio that suits your beans and method, keep it and adjust only one variable at a time. This calculator keeps those numbers fast and reliable so you can focus on flavor rather than math.

If you want even more control, note your yield and extraction. A higher yield with the same dose can taste thinner, while a lower yield can taste syrupy. Use the ratio as your foundation and refine grind, agitation, and brew time to reach your ideal cup. Small, repeatable steps beat random tweaking.

Formula

Ratio: R = water / coffee.

If water is known: coffee = water / R. If coffee is known: water = coffee × R.

Example Calculation

You want 500 g of water for a French press. The ratio is 1:16, so coffee = 500 / 16 = 31.25 g. The calculator outputs 31.3 g coffee and 500 g water for a balanced brew.

FAQs

Why is my coffee too strong?

Try a higher ratio (more water) or a coarser grind to reduce extraction.

Does temperature matter?

Yes. Hotter water extracts more quickly; cooler water can taste under-extracted.

Can I use this for cold brew?

Yes. Cold brew often uses ratios around 1:16–1:18 depending on concentrate strength.

Is this calculator private?

Yes. All calculations run locally in your browser.

How it works

This tool applies the selected brew ratio and solves for coffee or water based on your input. All computation is client-side for privacy.