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Coffee to Water Ratio Calculator

Turn a brew ratio into an exact recipe. Enter a ratio and one amount to get the coffee, water, cups, and tablespoons of grounds.

Brew strength

1:16
Balanced

Coffee to water, by weight. A lower number is stronger; 1:15 to 1:17 suits most filter and pour-over brews.

What do you know?

Enter the one value you have and the rest is worked out. Calculated in your browser; nothing is uploaded.

Used to count cups. A mug is about 250 ml; a small cup about 150 ml.

Recipe
15.6 g
Ground coffee at 1:16
250
Water (grams)
250
Water (ml)
1
Cups
3.1
Ground coffee (tbsp)

At 1:16, every 1 g of coffee uses 16 g of water, which is 16 ml since water weighs about 1 g per ml. Tablespoons assume roughly 5 g of grounds each and vary with grind.

How to calculate a coffee to water ratio

  1. Set the strength

    Drag the slider or tap a preset such as 1:16 to choose how strong the brew should be, from a heavy 1:14 to a light 1:18.

  2. Enter one amount

    Pick whether you know the water, the coffee, or the number of cups, then type that single value; everything else is worked out at once.

  3. Read or copy the recipe

    The ground coffee, water in grams and milliliters, cups, and tablespoons update live, and one tap copies the full recipe.

Why use this tool

Start from any known value

Enter the water in your kettle, the coffee on your scale, or the cups you want to pour, and the calculator fills in the rest.

Strength slider and presets

Slide anywhere from a 1:4 concentrate to a light 1:20, or tap the common filter ratios between 1:14 and 1:18.

Grams, milliliters, cups, and spoons

See the water as both weight and volume, the servings for your cup size, and an approximate tablespoon count for when no scale is handy.

Adjustable cup size

Set the cup size in milliliters to match your own mug so the cup count reflects how you actually pour.

Free with no signup

Open the page and start typing. There is no account, no limit, and nothing to install.

About this tool

This coffee to water ratio calculator turns a brew ratio into an exact recipe. Pick a strength on the slider or tap a preset like 1:16, then enter the one thing you already know, whether that is the water in your kettle, the coffee on your scale, or the number of cups you want to pour. It works out the rest instantly: ground coffee in grams, water in both grams and milliliters, the number of cups, and an approximate count of tablespoons of grounds for when a scale is not to hand.

Ratios are the reliable way to scale a recipe up or down without guesswork. A lower second number, such as 1:14, gives a stronger, heavier cup, and a higher one, such as 1:18, gives a lighter, cleaner brew. The tool assumes water weighs about 1 gram per milliliter, so the gram and milliliter figures for water match, and it lets you set the cup size in milliliters to suit your own mug. Tablespoons are an estimate at roughly 5 grams of grounds each and will shift with grind size and bean, so weigh whenever you can.

Switching between water, coffee, and cups keeps your numbers in place, so you can start from a full kettle and see how much coffee to grind, then flip to coffee to check how far a bag will stretch. To simplify or scale a plain ratio outside the kitchen, use the ratio calculator, and to move between grams, ounces, and other units, the unit converter handles the conversions.

Frequently asked questions

What does a coffee ratio like 1:16 mean?
It means 1 part coffee to 16 parts water, by weight. So 20 grams of coffee pairs with 320 grams of water. A smaller second number is stronger, a larger one is lighter.
What is the golden ratio for coffee?
A common starting point is between 1:15 and 1:18, with 1:16 or 1:17 often called the golden ratio for filter and pour-over coffee. Adjust to taste; the slider covers 1:4 to 1:20.
Why are the water grams and milliliters the same?
Water weighs about 1 gram per milliliter, so its weight in grams and its volume in milliliters are effectively equal. The calculator shows both so you can measure with a scale or a jug.
How accurate are the tablespoons?
Tablespoons are an estimate based on roughly 5 grams of ground coffee per tablespoon. The real weight varies with grind size, bean, and how you scoop, so a scale is always more precise.
Can I change the cup size?
Yes. Set the cup size in milliliters to match your mug. A large mug is around 250 ml and a small cup around 150 ml, which changes how many cups a given amount of water makes.
Is anything I type uploaded?
No. Every calculation happens in your browser. Nothing you enter is sent to a server, stored, or logged.

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