The widely accepted golden ratio for pour over coffee is 1:16 — that's 1 gram of coffee for every 16 grams (or ml) of water. This is the SCA (Specialty Coffee Association) recommended starting point. For a standard 350ml pour over, use approximately 22g of medium-fine ground coffee. Adjust slightly: use 1:15 for a bolder cup or 1:17 for a lighter, more delicate extraction. The ideal water temperature is 195–205°F (90–96°C).

French Press typically uses a stronger ratio of 1:14 (compared to 1:16 for pour over) because the immersion brewing method extracts less efficiently than percolation. The coarse grind and full-immersion style benefit from a slightly higher coffee dose. Common French Press ratios range from 1:12 (strong) to 1:15 (milder). Since the coffee steeps directly in water for 4–5 minutes, a stronger ratio helps achieve a full-bodied, rich cup without over-extraction bitterness.

Cold brew uses a much more concentrated ratio — typically 1:4 to 1:8 — because cold water extracts compounds from coffee much more slowly than hot water. A 1:5 ratio creates a concentrate that you can later dilute with water, milk, or ice (usually 1:1 or 1:2 concentrate to diluent). This concentrate can be stored in the refrigerator for up to 2 weeks. If you were to use a standard 1:16 ratio with cold water, the resulting brew would be very weak and under-extracted due to the lack of heat-driven extraction.

While a digital kitchen scale is highly recommended for accuracy (and they're quite affordable at $15–30), you can approximate: 1 level tablespoon of whole coffee beans ≈ 5–7 grams, and 1 tablespoon of ground coffee ≈ 5 grams. So for a 1:16 ratio with 250ml water, you'd need about 3 tablespoons of ground coffee. Note that grind size, bean density, and roast level all affect volume measurements, so results will vary. For consistent brewing, invest in a scale — it's the single most important coffee tool after a good grinder.

Starbucks typically uses a ratio of approximately 1:18 to 1:20 for their standard drip coffee, which is slightly weaker (more water per gram of coffee) than the SCA-recommended 1:16–1:18 range. This creates a milder, more approachable flavor profile suited to high-volume service. For their espresso, Starbucks uses a traditional Italian-style ratio of about 1:2 to 1:2.5, pulling ristretto-style shots for their handcrafted beverages.

Grind size and ratio work together to determine extraction. Finer grinds expose more surface area and extract faster — you may want a slightly weaker ratio (1:17) to avoid bitterness. Coarser grinds extract more slowly and can benefit from a stronger ratio (1:14) or longer brew time. As a general guide: Pour Over uses medium-fine (like table salt), French Press uses coarse (like sea salt), Espresso uses very fine (like powdered sugar), and Cold Brew uses extra-coarse (like coarse sea salt). Always adjust ratio based on taste — if your coffee tastes bitter, try a coarser grind or weaker ratio; if sour/weak, try a finer grind or stronger ratio.

In coffee brewing, 1 ml of water weighs exactly 1 gram at standard temperature, which is why coffee ratios are often expressed as a simple weight-to-weight ratio like 1:16. This means 1g of coffee to 16g of water, which is the same as 1g coffee to 16ml water. This convenient 1:1 relationship makes metric measurements ideal for coffee brewing. Note that US fluid ounces are different: 1 fl oz ≈ 29.57 ml, and 1 US cup = 8 fl oz ≈ 237 ml. For the most precise results, always use grams for both coffee and water.

Assuming a standard US "cup" of coffee is 8 fl oz (about 237ml), 4 cups = 948ml of water. At the recommended 1:16 ratio, you would need approximately 59 grams of coffee (about 10–12 tablespoons of whole beans). For a stronger brew at 1:14, use about 68 grams. Most home drip machines' "cup" markings actually refer to 5–6 oz cups, so check your specific machine. A typical 12oz bag of coffee (340g) will yield approximately 5–6 full pots (4 cups each) at the standard 1:16 ratio.