Coffee Ratio Calculator (2026): Grams & Water Chart

Coffee ratio calculator: how much should you use?

1:16 means 1 gram of coffee for 16 grams of water. Divide water grams by 16 to find coffee grams, or multiply coffee grams by 16 to find water grams. The calculator converts the known water quantity before doing the ratio math, so you do not mix grams with cups.

Water conversions: 1 ml ≈ 1g; 1 US fl oz ≈ 29.57g; 1 US cup ≈ 236.59g. A weight ounce is 28.35g. Coffee Bros covers cups, ounces, grams, and ml across eight methods, while Good Calculators explains the practical ml-to-gram shortcut.

What do you need?

You need coffee, water, your brewer, and preferably a scale that reads grams. Weigh grounds rather than converting tablespoons whenever possible because grind size and how tightly a spoon is filled change the dose. If you need equipment, see Best Coffee Scale for Espresso and Pour Over (2026).

• A gram-reading scale or marked water jug
• Coffee grounds and water
• Your brewer and its recipe

The Greater Goods listing specifies a 12.3 oz scale made with ABS and silicone, an integrated count-up/count-down timer, and a dishwasher-safe silicone cover. Those extras are convenient, not required for better coffee.

How do you choose and calculate a ratio?

Choose your brewer, pick a starting ratio, and enter whichever amount you already know. Calculate the other ingredient, then weigh and brew. These amounts set strength, not the whole flavor: extraction is how much flavor water pulls from the grounds, and grind, temperature, and time affect it.

1. Choose your brew method

Match the method before choosing strength. This compact chart gives starting points, not rules:

• Drip/pour-over: 1:16. Bean Box uses this standard; Home Grounds gives a lighter 1:17 pour-over example.
• French press: 1:12. Bean Box suggests this richer setting; try 1:15 if it feels too heavy.
• AeroPress: 1:16 for a full-strength starting cup. Concentrated recipes differ. See Best AeroPress Coffee Ratio (2026): 5 Proven Setups for Better Cups for dose, water, and strength setups.
• Chemex/siphon: try 1:16–1:17. These are starting suggestions, not fixed brewer requirements.
• Cold brew: try 1:8 concentrate or 1:16 ready to drink. A concentrate needs dilution after filtering.

2. Select strength

Start at 1:16 for filter coffee. Choose 1:15 for more heft or 1:17 for a lighter cup. A smaller second number means more coffee for the same water.

3. Enter water or coffee

Choose the amount you know and its unit. For water, use the amount added to the grounds, not finished coffee. For grounds, select grams or weight ounces, never milliliters.

4. Calculate the missing amount

• Coffee grams = water grams ÷ ratio number. Example: 600 ÷ 16 = 37.5g coffee.
• Water grams = coffee grams × ratio number. Example: 20 × 17 = 340g water, about 340 ml.

5. Weigh and brew

Put your container on the scale and press tare to reset it to zero. Weigh the grounds, reset again, then measure the water. Follow your recipe for grind and brew time, and note the ratio alongside your taste notes.

Which measurement mistakes should you avoid?

Check what each unit measures before brewing. Fluid ounces measure volume; ordinary ounces measure weight. A US measuring cup is also different from the small “cup” marked on many coffee machines. Use actual water volume or weight instead of relying on the machine's serving count.

• Counting rinse water: Discard filter-rinse water before measuring your brewing water.
• Using finished yield: Grounds hold water, so your drink weighs less than the water added.
• Mixing in espresso: Espresso's 1:2 describes coffee dose to beverage output, not reservoir water.

Why does the coffee still taste wrong?

Fix thin or heavy coffee with the ratio; investigate grind and brew time when the cup tastes sharply sour or drying. Change one thing per brew so you can tell what helped. No calculator can promise sweetness from amounts alone.

• Thin but pleasant: Try 1:15 instead of 1:16.
• Heavy but pleasant: Try 1:17, or add a little water after brewing.
• Lemon-sharp: Keep the ratio and try a slightly finer grind or longer steep.
• Bitter and drying: Try a coarser grind or shorter steep before adding more coffee.

For AeroPress, steeping and dilution can matter as much as dose. Use Best AeroPress Coffee Recipe (2026): 5 Methods Compared when you need a complete recipe rather than just a ratio.

Frequently asked questions