How Many Cups of Coffee from a 12 oz Bag?

You’ve got a shiny new 12-ounce bag of Stone Creek Coffee beans sitting on your counter. It smells amazing, you’re ready to brew, but maybe your curiosity has taken over. How much does a 12 oz bag of coffee make? And while we’re at it, how do coffee bag sizes work anyway? Let’s break it down so you can get the most cups possible from every bag.

Coffee Bag Sizes 101

In the U.S., the most common retail coffee bag sizes are 12 ounces, 16 ounces (1 pound), and larger 2-pound or 5-pound bags for serious at-home brewers or cafés.

Why 12 ounces? It’s a sweet spot - big enough to last a casual coffee drinker about two weeks, small enough to keep beans fresh until the last scoop. At Stone Creek Coffee, we roast in small batches so your 12 oz bag is packed with peak-flavor beans, ready to brew.

How long does coffee stay fresh? Read this blog post for more on how to keep your coffee fresher for longer. 

How Much Does a 12 oz Bag of Coffee Make?

Here’s the math:

• 12 ounces of whole beans = about 340 grams.

• The “golden ratio” for coffee is roughly 1 gram of coffee for every 16–18 grams of water (about 1:16–1:18 coffee-to-water ratio).

Using a 1:16 ratio, that means:

• 340g coffee × 16 = 5,440g water → about 5.4 liters of brewed coffee.

• That’s roughly 182 ounces of coffee total.

If you think in mug terms, that’s about:

• Twenty-five 6-oz cups

• Or fifteen 12-oz travel mugs

Of course, your mileage may vary depending on how strong you like your brew and what brewing method you use. French press drinkers might use more coffee per cup; pour over fans might stretch it farther.

How Much Coffee Grounds for 12 Cups of Coffee?

Here’s where it gets tricky—“12 cups” means different things depending on your coffee maker. Most drip machines call a “cup” 5–6 ounces, not the standard 8-ounce measuring cup you’d use in baking.

If we use the drip-machine definition (6 oz per cup), 12 cups is 72 ounces of coffee. With the 1:16 ratio:

• 72 oz water ≈ 2,040 grams

• 2,040 ÷ 16 = about 127 grams of coffee (around 4.5 ounces)

So if you’re brewing 12 “machine cups,” you’ll use roughly one-third of a 12 oz bag. That means you can get three full 12-cup pots from one bag, plus a little extra for a smaller batch.

Pro Tips to Maximize Your 12oz Bag

1. Grind Fresh – Grinding right before brewing keeps flavor locked in longer.

2. Use a Scale – It’s the best way to stick to your preferred coffee-to-water ratio every time.

3. Store Smart – Keep beans in an airtight container, away from light, heat, and moisture.

4. Dial in Your Brew – If it tastes weak, add a bit more coffee; if it’s too strong, ease back.

Bottom line: A 12 oz bag of coffee makes around 25 small cups or 15 big mugs, depending on your brew method and strength preferences. And now that you know exactly how many coffee grounds for 12 cups of coffee, you can make every last scoop count.