Espresso Ratio Calculator
Espresso yield and time from dose and style.
What it does
Espresso runs on ratios, not ounces. One part dry coffee to two parts liquid makes normale, one to one-and-a-half makes a syrupy ristretto, and one to three makes a long mild lungo. An 18 g dose becomes 27, 36, or 60 g across the three styles.
The tool above converts dose to yield with shot times attached. Enter grams, pick the style, and it prints yield, the time window, and the ratio label. Defaults give 36 g in 25-30 seconds; ristretto shortens to 27 g while lungo stretches 20 g to 60.
Coffee authorities agree on the center. NCA espresso guidance states 1:2 by weight with 20-30 second contact, and an SCA survey of working baristas averages 18-20 g doses to 36.5 g output at 1:2 in 25-30 seconds. Heritage definitions and modern averages coincide.
Grind steers the clock at fixed dose. Finer beds slow shots toward ristretto territory while coarser beds open toward lungo, so dial grind to land yield inside the time window. Weigh every shot; volume lies with crema.
How to use
- Enter the dry dose in grams.
- Pick ristretto, normale, or lungo.
- Read the yield first, then time.
- Grind to hit the time window.
- Weigh output, stop at yield.
- Taste and adjust finer or coarser.
Formula
- dose
- Dry coffee in grams, 0 to 100.
- ratio
- 1.5 ristretto, 2 normale, 3 lungo.
NCA states 1:2 with 20-30 sec; SCA survey averages 1:2 (36.5 g from 18-20 g) in 25-30 sec.
Worked example
Example: 18 g normale
Defaults: 18 g dose, normale.
- Inputs: 18 g dose, normale 1:2.
- Yield: 18 x 2 = 36 g espresso.
- Time: 25 to 30 seconds.
- Survey check: averages land 36.5 g from 18-20 g.
- Tool shows 36 g espresso, 25 to 30 sec, 1:2 normale.
Reference table
| Dose | 1:1.5 | 1:2 | 1:3 |
|---|---|---|---|
| 14 g | 21 | 28 | 42 |
| 16 g | 24 | 32 | 48 |
| 18 g | 27 | 36 | 54 |
| 20 g | 30 | 40 | 60 |
| 22 g | 33 | 44 | 66 |
Limits
- Weight math only. Taste needs dialing in.
- Machine pressure and temp assumed standard.
- Basket size caps dose choices.
- Crema fools volume measures.
Common mistakes
- Eyeballing volume instead of weighing.
- One grind for all three styles.
- Ignoring dose when chasing yield.
- Stopping by color, not grams.
- Skipping distribution and tamping.
Try it yourself
Quick checks. Answers sit tucked under each question.
18 g ristretto?
18 x 1.5 = 27 g in 20 to 25 sec.
20 g lungo?
20 x 3 = 60 g in 30 to 35 sec.
Questions
How is yield figured?
Dose times ratio: 18 x 2 = 36 g normale; 18 x 1.5 = 27 ristretto; 20 x 3 = 60 lungo.
What are the three styles?
Ristretto 1:1.5 short and heavy; normale 1:2 balanced; lungo 1:3 long and light.
What shot time per style?
Normale 25-30 sec; ristretto 20-25; lungo 30-35. Grind sets the pace at fixed dose.
What is a standard double dose?
18-20 g in a double basket per SCA survey averages, yielding ~36.5 g at 1:2.
Does grind change the style?
Yes. Finer grinds slow shots toward ristretto lengths; coarser opens toward lungo.
Should I weigh shots?
Yes. Scales beat scoops: gram doses repeat while volume scoops drift with grind.