Coffee-to-Water Ratio Calculator (Grams & Cups)
Enter any one value — coffee, water, or cups — and get the perfect brew measurements for any ratio.
What this tool does
The coffee-to-water ratio is the single biggest lever you can pull to change the taste of your cup — bigger than grind size, bigger than water temperature, bigger than brew time. Too little coffee and the water passes right through without extracting enough flavor, leaving a sour, thin cup. Too much and you pull out every harsh, bitter compound the bean has to offer. The SCA (Specialty Coffee Association) defines the "golden cup standard" as 55 g of coffee per liter of water, which sits right at 1:18. Most home brewers land happiest between 1:15 and 1:17.
Edit any field and the others update automatically. Grams and millilitres of water are interchangeable (1 ml of water weighs 1 g). Tablespoons are approximate — a scale is always more accurate.
How to use this tool
Pick your target strength
Choose a ratio preset or drag the slider. 1:15 is strong and bold, 1:16 is the balanced all-rounder most coffee shops use, 1:17–1:18 is lighter and more delicate — good for bright, floral single origins.
Enter what you know
Type into whichever field you're starting from — your coffee bag weight, your carafe's water capacity, or the number of cups you're brewing. All three fields update in real time.
Check the tablespoon estimate
If you don't own a scale yet, the tablespoon readout gives you a usable approximation. Bear in mind a tablespoon of light-roast whole beans weighs about 4–5 g while dark roast grounds pack closer to 6 g, so buy a $10 scale when you can.
Brew and adjust
Taste the cup before you tweak the recipe. If it's too weak, drop the ratio by 1 (go from 1:16 to 1:15). If it's too strong or bitter, increase it. Make one change at a time.
Pro tips
- Always weigh water, not just coffee. Many brewers weigh coffee but eyeball the water — that wipes out half the benefit of measuring.
- Use the same ratio as a baseline, then adjust roast level. A light roast at 1:16 will taste completely different from a dark roast at 1:16.
- Cold brew uses a much lower ratio (1:8 for concentrate) — use the dedicated cold brew calculator for that.
- Espresso lives on a totally different scale (1:2 dose-to-yield). The espresso calculator handles that separately.
Why it matters
Repeatability is what separates a good home brewer from a great one. Writing down your ratio means you can reproduce a great cup tomorrow, next week, or after switching beans. It also makes troubleshooting simple: if one variable is locked, you only ever have to diagnose one thing at a time.
Frequently asked questions
What is the golden ratio for coffee?
The "golden ratio" is roughly 1:15 to 1:18 — one gram of coffee for every 15 to 18 grams of water. A 1:16 ratio (about 62 grams of coffee per liter) is the most popular all-purpose starting point.
How much coffee do I use per cup?
A standard mug is about 250 ml (250 g) of water. At a 1:16 ratio that is roughly 15–16 g of coffee, or about 2 slightly rounded tablespoons of whole beans.
What ratio should I use for French press vs pour over?
Pour over and drip do well at 1:16–1:17. French press is often brewed a touch stronger at 1:15. Espresso is a different scale entirely, usually 1:2.