Pour over coffee ratio: how much water for your grams of coffee
The usual pour over coffee ratio is 1 gram of coffee to 15–17 grams of water, most often 1:16. That means 18 g of coffee takes 288 g of water and 20 g takes 320 g. The only math is grams of coffee × ratio = grams of water; a smaller ratio number makes a stronger cup and a bigger one makes it lighter.
Water chart by grams of coffee
Weigh water in grams on a scale rather than measuring volume. One milliliter of water weighs about one gram, so a measuring jug gets you close.
| Coffee | 1:15 (stronger) | 1:16 (standard) | 1:17 (lighter) |
|---|---|---|---|
| 15 g | 225 g | 240 g | 255 g |
| 18 g | 270 g | 288 g | 306 g |
| 20 g | 300 g | 320 g | 340 g |
| 22 g | 330 g | 352 g | 374 g |
| 25 g | 375 g | 400 g | 425 g |
| 30 g | 450 g | 480 g | 510 g |
For one mug (about 250–300 ml), start with 15–18 g of coffee; for two, start around 30 g. The grounds hold back roughly twice their weight in water, so the cup ends up a little smaller than the water you pour.
Starting ratios by brewer
Each brewer extracts differently, so the starting ratio changes. Treat these as a starting point and adjust by 0.5 to 1 at a time.
| Brewer | Starting ratio | Notes |
|---|---|---|
| Pour over (V60), flat-bottom dripper | 1:15 – 1:17 | Bloom 30–45 s, then 2–4 pours |
| Chemex | 1:15 – 1:17 | Thick filter, grind a bit coarser |
| Clever dripper | 1:15 – 1:16 | Steep, then drain |
| AeroPress | 1:12 – 1:16 | Often brewed strong and topped up |
| French press | 1:12 – 1:16 | Coarse grind, about 4 minutes |
| Espresso | 1:1.5 – 1:3 | 18 g in, 36 g out is a common baseline |
| Cold brew | 1:5 – 1:8 (concentrate) | Dilute with water or milk |
Bloom with 2–3 times the coffee's weight
The bloom is the first pour: 2–3 times the coffee's weight in water, then a 30–45 second wait. For 18 g of coffee that is 36–54 g. It lets gas escape so the later pours soak in evenly. The bloom water counts toward the total.
What people miss when they change the dose
When you use more coffee, every pour target has to scale too, not just the total. "Pour to 144 g" in an 18 g recipe becomes 176 g at 22 g. A bigger dose also drains more slowly, so going one step coarser on the grinder can keep the brew time on track.
In Bloomcup
In a Bloomcup recipe, change the coffee with the − and + buttons and the water and every cumulative pour target are recalculated from your ratio right away. Set the ratio from 1:10 to 1:20 (1:1.5 to 1:3 for espresso) with a slider and see grind, water temperature and total time on the same screen. When you start, the big timer shows the target weight for your scale at each step, with no ads while you brew.
FAQ
- How much water for 20 g of coffee?
- At the standard 1:16 ratio, 320 g. For a stronger cup use 1:15 (300 g), for a lighter one 1:17 (340 g).
- Does the timer update based on grams of coffee?
- In Bloomcup, yes. Change the grams and the water and every pour target are recalculated for you.
- How do I make my coffee stronger?
- Lower the ratio number. Going from 1:16 to 1:15 uses less water for the same coffee, so the cup gets stronger.
- Can I measure water in ml instead of grams?
- One ml of water is about one gram, so it is close. A scale is still the easiest way to hit each pour target.
Set the grams and let Bloomcup work out every pour
Get Bloomcup on Google Play