Coffee Ratio Calculator
Calculate exact coffee and water amounts for drip, pour-over, French press, espresso, and cold brew.
Getting coffee ratios right made a bigger difference to my home coffee than any equipment upgrade. A kitchen scale accurate to one gram costs $10 and immediately improves every cup. The ratio is the foundation everything else builds on.
The SCA (Specialty Coffee Association) golden ratio is 1:15 to 1:18 for filter coffee, 55–65 grams of coffee per liter of water. Start at 1:16 and adjust from there based on taste.
Why ratios matter
Coffee strength and extraction are controlled by three variables: grind size, brew time, and ratio. The ratio determines the concentration of dissolved solids in the final cup, too low and the coffee tastes thin and acidic; too high and it tastes bitter and over-extracted. Using a consistent ratio by weight (not volume) removes one variable from the equation, letting you isolate grind size and brew time when troubleshooting.
Weight vs volume measurement
Coffee is correctly measured by weight in grams, not by scoops or tablespoons. Density varies significantly by roast level and bean type, a scoop of light roast contains more coffee by weight than a scoop of dark roast (which is less dense due to expanded cell structure from roasting). A tablespoon of coarsely ground coffee weighs significantly less than a tablespoon of finely ground. Weight-based measurement is the only way to brew consistently.
Brew method ratios explained
Pour-over (V60, Chemex): The 1:15–1:17 range produces a clean, nuanced cup. Chemex uses coarser grind and slightly more water (1:17) due to its thicker filter. French press: 1:12–1:15 for a fuller-bodied, immersion-brewed cup. The metal filter allows oils through, contributing to body. Espresso: 1:2 brew ratio (18g coffee → 36g espresso output) is the modern standard, though some prefer 1:2.5 for lighter roasts. Cold brew: 1:7.5–1:8 for concentrate (dilute 1:1 before serving), 1:15 for ready-to-drink strength brewed over 12–24 hours.
Dialing in your ratio
Start at the recommended ratio for your method. If the coffee tastes too strong or bitter, increase the ratio (more water per gram of coffee). If it tastes thin, watery, or sour, decrease the ratio (less water). Make one change at a time, changing both ratio and grind size simultaneously makes it impossible to know which change caused the improvement. Keep a simple log of what worked.
Frequently asked questions
Does water temperature matter?
Yes. The SCA recommends 90–96°C (195–205°F) for filter coffee, just off boil is close enough. Cooler water under-extracts, producing sour, flat coffee. Boiling water can over-extract and make coffee bitter. For cold brew, cold water extracts more slowly and selectively, producing lower acidity and sweetness.
What grind size should I use?
Coarser grinds extract more slowly; finer grinds extract faster. French press uses coarse (like coarse sea salt). Pour-over uses medium-fine (like table salt). Espresso uses fine (like powdered sugar). AeroPress is flexible, finer grinds with shorter brew time or coarser with longer, both can work.
Why does my coffee taste different even with the same ratio?
Water chemistry, bean freshness (coffee degasses significantly in the first 2–7 days after roasting and goes stale within 4–6 weeks), grind consistency, water temperature, and pour technique all affect extraction independent of ratio. Freshly roasted beans ground immediately before brewing make the single biggest quality difference.