Coffee Ratio by Cups Calculator
Tell it how many cups and how strong, and get the ground coffee and water — in grams, tablespoons and millilitres — to brew.
How it works
Water = cups × cup size (ml) · Coffee (g) = water (g) ÷ ratio · Tablespoons ≈ grams ÷ 5.3
Good coffee comes from a consistent coffee-to-water ratio by weight, since 1 ml of water weighs about 1 g. The Specialty Coffee Association’s "golden" range is roughly 1 : 15 to 1 : 18 — one part coffee to fifteen-to-eighteen parts water. Multiply your cup count by the cup size to get the water, then divide by the ratio for the grounds; a kitchen scale beats scoops every time.
Worked example
Brewing 4 cups of 240 ml each is 960 ml of water. At a medium 1 : 16 ratio that is 960 ÷ 16 = 60 g of coffee, roughly 60 ÷ 5.3 ≈ 11.3 tablespoons.
Frequently asked questions
What is the golden ratio for coffee?
About 1 part coffee to 15–18 parts water by weight. Nearer 1 : 15 brews strong and full, nearer 1 : 18 lighter and more delicate — this calculator maps mild, medium and strong onto that band.
Why weigh coffee instead of using scoops?
Grind size and bean density make a "tablespoon" vary a lot, so scoops give inconsistent strength. Weighing in grams — and treating 1 ml of water as 1 g — keeps every pot the same.
Is a coffee "cup" the same as a measuring cup?
Usually not. Coffee makers often rate a "cup" at about 5 oz (150 ml), while a US measuring cup is 240 ml. Set the cup size to match your machine or mug so the water total is right.
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This calculator is for educational purposes. Double-check important results before acting on them.