Coffee Calculator

About the Coffee Calculator

Great coffee comes down to four variables: the coffee-to-water ratio, grind size, water temperature, and contact time. Of these, the ratio is the foundation — get it right and everything else is fine-tuning. The Specialty Coffee Association (SCA) recommends a golden ratio of 1:15 to 1:18 (grams of coffee to grams of water), but every brewing method has its own optimal range, and personal taste plays a huge role.

Pour-over and drip coffee typically use 1:15 to 1:17 for a balanced cup. French press works best around 1:15 for a rich, full-bodied brew. Espresso uses a concentrated 1:2 ratio (18g in, 36g out). Cold brew concentrate starts at 1:5, meant to be diluted before drinking. AeroPress is uniquely flexible, with popular recipes ranging from 1:6 (strong concentrate) to 1:16 (traditional strength).

This calculator covers all major brew methods with their recommended ratios, grind sizes, temperatures, and brew times. Enter how many cups you want and your brew method, and it calculates the exact coffee and water measurements. It also adjusts for cup size (a "cup" of coffee varies from 6 oz at the SCA standard to 12+ oz at most cafes).

When This Page Helps

Use this to standardize recipes across brew methods, cup sizes, and strengths so each cup lands where you expect it.

How to Use the Inputs

1. Select your brewing method from the dropdown.
2. Enter the number of cups you want to brew.
3. Choose your desired strength (light, standard, or strong).
4. Select your cup size (standard 6 oz, large 10 oz, or mug 12 oz).
5. View the exact coffee dose, water amount, grind size, and brew time.
6. Use the comparison table to see how different methods compare.

Example Calculation

Tips & Best Practices

• Use a kitchen scale for coffee — scoops are inaccurate because grind size changes volume. Weight is consistent.
• Pre-wet paper filters before brewing to remove paper taste and preheat the vessel.
• Store beans in an airtight container at room temperature — never the fridge or freezer.
• Use water within 15 seconds of boiling for optimal temperature (~200°F).
• Adjust one variable at a time: if coffee is too strong, increase the ratio first before changing grind or time.
• Clean your equipment regularly — old coffee oils go rancid and make everything taste stale.

Brew Method Deep Dive

**Pour-Over (V60, Chemex, Kalita):** Ratio 1:15-17. Medium-fine grind. 200-205°F water. 3-4 minute brew time. Produces clean, bright, nuanced cups that highlight origin flavors. The technique (pour pattern, speed) matters more here than any other method. **French Press:** Ratio 1:14-16. Coarse grind. 200°F water. 4-minute steep. Full-bodied, rich, with natural oils (no paper filter). The most forgiving method for beginners. **Drip Auto:** Ratio 1:16-18. Medium grind. Temperature varies by machine. Set it and forget it — consistent but limited control.

Espresso: A Different Language

Espresso doesn't use the same ratio system as brewed coffee. Instead, it uses dose:yield ratios. **A standard espresso** uses 18g coffee to produce 36g of liquid (1:2) in 25-30 seconds. **Ristretto** is shorter: 18g in, 27g out (1:1.5) for a more concentrated, sweeter shot. **Lungo** is longer: 18g in, 54g out (1:3) for a milder, more bitter shot. The grind must be adjusted precisely — even small changes affect the extraction time and flavor dramatically.

Cold Brew: Patience Rewarded

Cold brew uses a much higher coffee-to-water ratio (1:5 to 1:8) because cold water extracts much less than hot water. The long steep time (12-24 hours) compensates, producing a smooth, low-acid concentrate meant to be diluted 1:1 with water or milk before drinking. A 1:5 ratio steeped for 18 hours, then diluted 1:1, produces a cup roughly equivalent to a 1:10 hot brew — smooth, sweet, and less acidic.

Frequently Asked Questions

• How much coffee per cup?

  The SCA standard is about 10g (2 tablespoons) of coffee per 6 oz cup of water. For a 12 oz mug, use about 20g. This gives a balanced cup at approximately 1:16 ratio.

• What is the golden ratio for coffee?

  The SCA golden ratio is 55g of coffee per liter of water, which works out to approximately 1:18. Most specialty coffee professionals prefer slightly stronger at 1:15 to 1:16.

• How many tablespoons of coffee per cup?

  About 2 tablespoons (10g) per 6 oz cup. For a standard 12 oz mug, use 3-4 tablespoons. A tablespoon of ground coffee is approximately 5-7g depending on grind size.

• Does grind size affect the ratio?

  Not the ratio itself, but grind size affects extraction. Fine grinds extract faster (espresso), coarse grinds slower (French press). Using the wrong grind for your method makes coffee bitter (too fine) or sour (too coarse).

• What temperature should the water be?

  Between 195-205°F (90-96°C) for most methods. Water that's too hot over-extracts (bitter), too cool under-extracts (sour, weak). Boil water and let it sit 30 seconds to reach ~200°F.

• Why is my coffee bitter?

  Over-extraction: the water pulled too many compounds from the grounds. Fix by using coarser grind, shorter brew time, lower temperature, or a slightly higher ratio (less coffee). Any one of these adjustments can help.