How many cups are really in a bag
"About 30 cups in a bag" is the answer every generic coffee blog gives, and it’s wrong for roughly half the people reading it, because it quietly assumes an 8–9 gram dose that almost nobody actually brews. Dose is the variable that decides everything, and it swings hard by method.
| Method | Typical dose | Cups from a 250 g bag |
|---|---|---|
| Espresso (double) | 18 g | 13 |
| Pour-over | 15 g | 16 |
| French press | 17 g | 14 |
| Drip machine | 12 g | 20 |
An espresso drinker and a drip-machine drinker can buy the identical 250 g bag and get a seven-cup swing in how far it stretches — 13 doubles versus 20 mugs — with nothing about the bag itself different. If your method isn’t weighed at all, the gap is even wider: a heaping, unweighed scoop can easily run 8–10 g, which is exactly how the inflated "30 cups" number gets produced in the first place. Weigh your dose once and every number this tool gives you becomes exact instead of a guess.
The freshness window
Roasted coffee doesn’t go bad the way milk does — it goes quiet. Right after roasting, beans are actively degassing carbon dioxide for several days, which is why fresh bags often ship with a one-way valve. Flavor and aroma peak somewhere in the first two to four weeks after the roast date, as the volatile aromatic compounds that make coffee smell like coffee are still mostly intact. From there, oxidation slowly strips those compounds away: the cup doesn’t become unsafe, it just gets flatter, duller and less complex with every passing week.
Once you open the bag, that clock speeds up. Every time air gets in — and it does, valve or not, every time you reach for a scoop — more of the aromatic compounds oxidize. Whole bean holds up noticeably better than pre-ground, because grinding multiplies the surface area exposed to oxygen by a factor of thousands; a bag you grind fresh each morning will taste better on day 20 than a bag you ground entirely on day 1.
This is exactly why a 1 kg bag is false economy for a single drinker having one cup a day: at a 15 g pour-over dose that’s roughly 67 days to empty it, more than double the 30-day freshness window this calculator flags. The per-gram price looks better on the bag in the store; the coffee in the cup by week six does not. A smaller bag bought more often almost always beats a big bag that outlives its own peak — the DABOV Coffee Club exists specifically to automate that smaller-more-often rhythm without you having to remember to reorder.
The true cost per cup
Cost per cup is one formula: bag price × dose ÷ bag size. Work a real example: a $22 bag of 250 g coffee, brewed at a 15 g pour-over dose, costs $22 × 15 ÷ 250 = $1.32 a cup. Add a splash of milk and you’re still well under $1.50. Compare that to a café: a drip coffee runs $3–4, a latte $5–7, and the gap between $1.32 and even the cheap end of that range is $2–6 every single cup.
Run the monthly math on the same numbers: two cups a day at $1.32 each is $2.64 a day, or about $79 a month. The same two cups a day at a $5 café habit is $300 a month. That’s roughly $221 a month — over $2,600 a year — staying in your pocket for making the same two cups yourself. Specialty coffee at home genuinely does run $1–1.60 a cup for most methods; café coffee genuinely does run $5–7. The math isn’t close.
None of this means the café always loses. You’re not just buying a cup of coffee there — you’re buying a seat, a barista who knows your order, a reason to leave the house. That’s a real thing worth paying for sometimes. But for the two or three cups most people drink at their own kitchen counter every single day, the honest math above is the number that should be setting your expectations, not the bag’s sticker price.
Right-sizing your supply
Match the bag to the habit, not the habit to the bag. A solo drinker having two 15 g pour-overs a day empties a 250 g bag in about 8.3 days — comfortably inside the freshness window with room to spare, which is why 250 g is this calculator’s default. Push that same person to a 1 kg bag and they’re now stretching the same habit past two months, well past the point where the back half of the bag tastes like a different, flatter coffee than the front half.
The math flips for busier households. Two espresso drinkers each having two 18 g doubles a day get through a 1 kg bag in 13.9 days — inside the window, and the calculator’s normative +1-day tolerance rounds that up to a "every 2 weeks" refill rather than the overly cautious "every week," since 14 days is close enough to 13.9 to not waste a trip. A four-person office running a drip machine at a lighter 12 g dose gets through the same 1 kg bag in about 10.4 days — comfortably inside the window on a weekly refill. Bigger households naturally earn the right to buy bigger bags; the freshness math, not the sticker price, is what should decide the size.
Storage that actually matters
Four things protect what freshness a bag has left: keep it airtight, keep it dark, keep it cool, and keep it out of the fridge. An airtight, opaque canister (or the bag itself, resealed and squeezed of excess air) slows oxidation the most of any single habit change. Light and heat both accelerate the same staling process, which is why a canister on the counter next to a sunny window undoes most of the benefit of buying a smaller, fresher bag in the first place.
The fridge is a trap, not a solution: every time a cold bag comes out into room-temperature air, moisture condenses on the beans, and wet beans stale faster than dry ones and risk mold on top of it. The freezer is the one legitimate exception — for coffee you won’t touch for weeks, portioning it into small sealed bags before freezing and thawing only what you’ll use in the next few days genuinely does extend the runway. For the bag you’re actively working through day to day, though, a simple airtight canister on a dark shelf beats any freezer trick — and buying a size that empties inside 30 days beats them both.
