Coffee Ratio Calculator

Last updated: March 24, 2026
Reviewed by: LumoCalculator Team

Calculate coffee dose, brew water, or espresso yield from method-based starting ratios so you can size a single cup, a French press batch, a cold brew prep, or a shot target before brewing.

Coffee Ratio Inputs

Calculate from
Brewing method

Coffee Ratio Summary

Coffee dose

20 g

Pour over starting point

Brew water

320 ml

Water to heat before brewing

Approximate servings: 1.3 cups (240 ml each).

Starting ratio

1:16

Manual filter brew with bloom and steady pours.

Grind size

Medium-fine

Adjust finer or coarser only after taste testing

Water temperature

93 +/- 3 C

Hotter water extracts faster

Brew time

2-4 minutes

A longer contact time usually extracts more

Current Calculation

Brew water = coffee dose x ratio

20 x 16 = 320 ml

Reverse-check the dose

320 / 16 = 20 g

Planning note

For brew planning, 1 ml of water is treated as roughly 1 g of water when you weigh the kettle or brewer.

Method Details

Brewing methodPour over
Starting ratio1:16
Coffee dose20 g
Brew water320 ml
Grind sizeMedium-fine
Water temperature93 +/- 3 C
Brew time2-4 minutes
Approx. servings1.3 cups (240 ml each)

Use Scenarios

Dial in a single cup

Start with a pour-over, drip, or AeroPress preset when you want one repeatable mug instead of guessing from scoops or memory.

Scale a batch cleanly

Reverse the math from brew water to coffee dose when you are planning a French press or automatic-drip batch for more than one person.

Compare stronger brew styles

Use the method presets to see why espresso and cold brew need much lower ratio numbers than filter coffee even before you adjust for taste.

Formula Explanation

1) Forward brew math

Liquid target = coffee dose x ratio

When you already know the coffee dose, multiply it by the method ratio to size brew water for filter coffee or beverage yield for espresso.

2) Reverse the equation

Coffee dose = liquid target / ratio

When you know how much liquid you want to brew, divide by the ratio to find the grams of coffee to weigh out.

3) Weight-first planning

1 ml water is treated as roughly 1 g water

Using grams and milliliters makes the calculator easy to scale. It also avoids the inconsistency that comes from tablespoons or scoops.

4) Method starting presets

Pour over 1:16 | French press 1:15 | Espresso 1:2 | Drip 1:17 | Cold brew 1:5 | AeroPress 1:15

These are starting points rather than universal rules. Different filters, roasts, grind sizes, and taste goals can all justify a stronger or lighter ratio.

How to Read the Result

Coffee dose

Treat the coffee number as the dry dose to put on the scale before grinding or brewing. If the cup tastes weak, you can increase dose by lowering the ratio number or brewing a smaller liquid target.

Liquid target

For filter coffee and cold brew, the liquid target is brew water. For espresso, the liquid target is beverage yield in the cup, because shot ratios are not written as total machine water.

Taste adjustments

A lower ratio number means more coffee for the same liquid and usually a stronger cup. A higher ratio number means less coffee for the same liquid and usually a lighter cup.

Example Cases

Case 1: Single-cup pour over

Inputs

  • Coffee dose: 20 g
  • Method: Pour over
  • Starting ratio: 1:16

Computed Results

  • Coffee dose: 20 g
  • Brew water: 320 ml
  • Grind size: Medium-fine
  • Brew time: 2-4 minutes

Interpretation

This is a practical one-mug baseline for manual filter coffee. It stays close to a standard 1:16 starting point without pushing the cup too strong or too light.

Decision Hint

Use a case like this when you want a repeatable morning brew and plan to adjust only one variable at a time after tasting.

Case 2: French press for two

Inputs

  • Liquid target: 600 ml
  • Method: French press
  • Starting ratio: 1:15

Computed Results

  • Coffee dose: 40 g
  • Brew water: 600 ml
  • Grind size: Coarse
  • Brew time: 4 minutes

Interpretation

Calculating backward from the brew-water target makes it easy to size a bigger immersion batch without guessing how many tablespoons to use.

Decision Hint

Choose a reverse-calculation case like this when you know your carafe size first and want the coffee dose to follow automatically.

Case 3: AeroPress travel mug

Inputs

  • Liquid target: 240 ml
  • Method: AeroPress
  • Starting ratio: 1:15

Computed Results

  • Coffee dose: 16 g
  • Brew water: 240 ml
  • Grind size: Medium-fine
  • Brew time: 1-2 minutes

Interpretation

AeroPress uses a tighter ratio than standard drip, so a single-mug target still needs a clearly measured coffee dose to avoid a weak travel brew.

Decision Hint

Use this type of case when you want one quick cup and prefer to size the coffee from the mug volume you plan to fill.

Boundary Conditions

The calculator assumes weight-based brewing. Use a scale if you want the result to be repeatable from one brew to the next.
Cup counts are shown only as rough planning help based on 240 ml per cup. They do not account for water retained in the grounds or for mug sizes larger than 8 oz.
Espresso uses beverage yield rather than total machine water, so the espresso result should be read as what lands in the cup.
Cold brew is shown as a concentrate-style starting point. If you prefer ready-to-drink cold brew, you may choose a lighter ratio or dilute after brewing.
The ratio does not replace grind-size control, water temperature, or brew time. A correct ratio with the wrong grind can still taste sour, weak, or bitter.
Method presets are starting points, not standards that fit every bean. Roast level, processing, and filter type can all justify moving the ratio up or down.

Sources & References

Frequently Asked Questions

What coffee-to-water ratio should I start with for pour-over or drip coffee?
A practical home-brew starting point is 1:16 for pour-over and about 1:17 for automatic drip. If the cup tastes too light, lower the ratio number slightly. If it tastes too heavy or bitter, raise it slightly.
Is 1 milliliter of water the same as 1 gram here?
For brew planning, yes. Water is close enough to 1 g per 1 ml that coffee calculators can use grams and milliliters interchangeably for normal kitchen brewing.
Do I really need a scale, or can I use scoops and tablespoons?
A scale is the better option if you want repeatable coffee. Scoop and tablespoon measurements shift with roast level, grind size, and how tightly the grounds pack, while grams stay consistent from brew to brew.
Why does cold brew need so much more coffee than hot coffee?
Cold brew extracts more slowly, so many recipes start with a much stronger concentrate than hot filter coffee. That is why its ratio number is lower and the coffee dose climbs quickly.
Why does the espresso result show yield instead of brew water?
Espresso ratios are written as dry dose to beverage yield in the cup. A 1:2 shot means 18 g of coffee in and about 36 ml out, even though the machine passes more water through the puck during extraction.
Should I change the ratio or the grind size first when the cup tastes off?
If your recipe is already close to the style you want, change grind size first to fix under- or over-extraction. Change the ratio when you want the cup to be clearly stronger or lighter overall.
Coffee Ratio Calculator - Dose & Water by Method