By Miles SinclairUpdated November 2026
A pour-over coffee ratio calculator turns one simple number into a repeatable brew: how many grams of water to pour for each gram of coffee. Enter your dose and target strength, and you get the exact water weight to use. This guide shows you how to run the math, choose a starting ratio, and adjust it based on taste.
Why the Ratio Matters More Than the Recipe
Ratio controls strength. Water volume is easy to eyeball, but grams are not. A tablespoon of ground coffee can weigh anywhere from about 5 to 7 grams depending on grind size and roast, so measuring by scoop makes results inconsistent. Weighing both coffee and water removes that guesswork and lets you compare brews fairly.
Shopping for one? See our guide: 7 Best Pour Over Coffee Dripper Models for Home Brewers (2026).
How to Calculate Your Brew Water
The formula is simple: water grams = coffee grams × ratio. If you use 20 grams of coffee at a 1:16 ratio, you need 320 grams of water. Most pour-over drinkers start between 1:15 and 1:17. Lighter, more delicate roasts often taste good at the higher end, while darker roasts can be brewed a bit stronger.
- Pick your coffee dose, such as 15, 20, or 25 grams for one or two cups.
- Choose a starting ratio, such as 1:16.
- Multiply the dose by the ratio to get total water weight.
- Pour in stages, keeping the total at your target weight.
Starting Ratios by Cup Size
Use this table as a baseline, then adjust for taste. Each row assumes a 1:16 ratio.
| Coffee Dose | Water Weight (1:16) | Typical Yield |
|---|---|---|
| 15 g | 240 g | One mug |
| 20 g | 320 g | One large mug or two small cups |
| 25 g | 400 g | Two standard mugs |
Adjusting the Ratio to Fit Your Taste
Once you have a brew you like, change one variable at a time. If the cup tastes flat or weak, lower the ratio (for example, from 1:16 to 1:15) so you use more coffee or less water. If it tastes harsh, dry, or overly strong, raise the ratio toward 1:17. Grind size and water temperature also affect extraction, so adjust those separately when you need a larger change. For more on those variables, see Coffee Grind Size for Pour Over: A Step-by-Step Guide for Better Flavor.
Keep a Brew Log
Write down your dose, water weight, grind setting, water temperature, and brew time. Small notes make it much easier to repeat a cup you enjoyed and to track what changed when a brew tastes off.
Common Mistakes
- Measuring coffee by volume instead of weight, which causes large swings in strength.
- Changing the ratio and the grind at the same time, so you cannot tell which change helped.
- Forgetting to account for the water absorbed by the grounds, which can slightly reduce the final yield.
- Using a ratio that is too strong for a light roast, leading to sourness or thin body.
- Ignoring water temperature. If a cup tastes bitter, Why Is My Pour Over Coffee Bitter: 5 Causes and Fixes for a Smoother Cup covers the most likely causes.
Recommended Gear
A digital scale that reads in one-gram increments is the most useful tool for this method, since it lets you weigh coffee, bloom water, and total brew water accurately. A gooseneck kettle gives you controlled pours, which helps keep the water weight steady from stage to stage. A dedicated coffee scale with a built-in timer is also helpful for tracking brew time.
- A digital coffee scale with a timer, so you can weigh and time every brew. View on Amazon
- A gooseneck kettle for steady, controlled pours. View on Amazon
FAQ
What is a good starting ratio for pour-over coffee?
A ratio of 1:16 is a common starting point, meaning 16 grams of water for every gram of coffee. You can move up or down by about 1 point to fit your taste.
Does the ratio change with different brewers?
The ratio is about strength, so the same starting point works across most pour-over cones. Brewer design affects flow rate and extraction time, which may call for small grind or pour adjustments.
Should I include the bloom water in my total?
Yes. Your total brew water includes the bloom and all later pours, so the scale should read your full target weight by the end of the brew.
Conclusion
A pour-over coffee ratio calculator takes the guesswork out of brewing. Weigh your coffee, multiply by your chosen ratio, and pour to that exact weight. Log your results and adjust one variable at a time until the cup tastes the way you want.
Related reading
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About Miles Sinclair
Miles Sinclair is part of our editorial team and reviews and edits our coffee beans & brewing methods guides, checking product details against manufacturer specifications and owner feedback.
