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Coffee Ratio Calculator

The Coffee Ratio Calculator helps you brew the perfect cup by calculating the ideal coffee-to-water ratio for your brewing method. Enter your desired strength and serving size to get precise measurements in grams and milliliters.

Coffee Ratio Calculator — Live Preview
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Quick interactive ratio calculators — solve proportions, scale values, and simplify ratios.

Proportion Solver

Provide any three values below to calculate the fourth in the ratio A : B = C : D.

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Solved Proportion
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Simplified
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Percentages
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Visual Ratio
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    Scale Multiplier

    Scale a ratio up or down by a multiplier.

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    Scaled Ratio
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    Original
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    Factor
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    Percentages
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      Simplifier

      Reduce any ratio to its simplest form.

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        What is Coffee Ratio?

        Coffee ratio is the proportion of coffee grounds to water used in brewing. The Specialty Coffee Association (SCA) recommends a golden ratio of 1:15 to 1:18 (grams of coffee to grams of water). A 1:16 ratio means 1 gram of coffee per 16 grams (ml) of water — producing a balanced, medium-strength cup.

        Different brewing methods require different ratios: espresso uses 1:2 (very concentrated), French press 1:15, pour-over 1:16, and cold brew 1:8 (strong concentrate diluted later). Understanding coffee ratios ensures consistency and allows you to fine-tune strength to personal taste.

        Formulas & Equations Used

        This Coffee Ratio Calculator uses the following core equations:

        1 Coffee Amount ▼
        Coffee (g) = Water (ml) / Ratio

        For 500ml of water at 1:16 ratio: Coffee = 500 / 16 = 31.25 grams.

        2 Water Amount ▼
        Water (ml) = Coffee (g) × Ratio

        Using 20g of coffee at 1:15 ratio: Water = 20 × 15 = 300 ml.

        3 Cups to Volume ▼
        Water (ml) = Number of Cups × Cup Size (ml)

        3 cups at 250ml each = 750ml total water needed.

        How to Use This Coffee Ratio Calculator

        Follow these 3 simple steps:

        1

        Enter Your Values

        Type the known values into the input fields above. The Coffee Ratio Calculator accepts any positive numbers.

        2

        Choose Calculation Mode

        Select Solve, Simplify, or Scale mode in the calculator. Each applies different equations to your inputs.

        3

        View Results

        Click Calculate to see your answer with a visual ratio bar, pie chart, and step-by-step solution breakdown.

        Example Problems & Step-by-Step Solutions

        Here are 3 worked examples using this Coffee Ratio Calculator:

        Example 1 Pour-over: 2 cups at 1:16 ratio
        1 Water: 2 × 250ml = 500ml
        2 Coffee: 500 / 16 = 31.25g
        3 Round to 31g for practical measurement
        ✓ Use 31g coffee with 500ml water
        Example 2 French press: 1 liter at 1:15 ratio
        1 Water: 1000ml
        2 Coffee: 1000 / 15 = 66.7g
        3 Grind: coarse (sea salt texture)
        ✓ Use 67g coarse-ground coffee with 1 liter water
        Example 3 Cold brew concentrate: 500ml at 1:8 ratio
        1 Water: 500ml
        2 Coffee: 500 / 8 = 62.5g
        3 Steep 12-24 hours, then dilute 1:1 with water
        ✓ Use 63g coffee, steep 18 hours, dilute before serving

        Frequently Asked Questions

        What is the golden ratio for coffee? ▼

        The SCA golden ratio is 1:15 to 1:18 (1 gram coffee per 15-18 grams water). For most drip and pour-over methods, 1:16 produces a well-balanced cup. Adjust stronger (1:14) or lighter (1:18) to taste.

        How many grams of coffee per cup? ▼

        For a standard 250ml (8.5 oz) cup at 1:16 ratio, use about 15-16 grams of coffee. For a stronger cup (1:14), use about 18 grams. For a lighter cup (1:18), use about 14 grams.

        What ratio is best for espresso? ▼

        Standard espresso uses a 1:2 ratio — 18g of finely ground coffee yields 36g of espresso in 25-30 seconds. Ristretto uses 1:1.5 (shorter, more concentrated), and lungo uses 1:3 (longer, milder).

        Why should I weigh coffee instead of using scoops? ▼

        Coffee density varies by roast level and grind size. A scoop of light roast weighs more than the same scoop of dark roast. A digital scale (accurate to 0.1g) ensures consistent ratios and reproducible results.

        What ratio should I use for cold brew? ▼

        Cold brew uses 1:5 to 1:8 ratio for concentrate, then dilute 1:1 or 1:2 with water or milk when serving. Start with 1:8 for a versatile concentrate — you can always add more water but can't strengthen a weak brew.

        Learn About Ratios

        What is a ratio?

        A ratio is a comparison between two or more quantities showing the relative size of one to another. Written as A : B, it means 'for every A units of the first quantity, there are B units of the second.' For example, a ratio of 3 : 4 means for every 3 parts of A, there are 4 parts of B. Ratios are used in cooking, construction, finance, science, and everyday life.

        How do I solve a proportion?

        A proportion is an equation that says two ratios are equal: A : B = C : D. To solve for a missing value, use cross-multiplication. If D is unknown: D = (B × C) / A. This works because in equal ratios, the cross products are always equal: A × D = B × C. Our Proportion Solver does this automatically — just enter any 3 values and it finds the 4th.

        How do I simplify a ratio?

        To simplify a ratio, find the Greatest Common Divisor (GCD) of both numbers and divide each by it. For example, 24 : 36 — the GCD of 24 and 36 is 12. So 24 ÷ 12 = 2 and 36 ÷ 12 = 3, giving the simplified ratio 2 : 3. Our Simplifier automatically finds the GCD and reduces your ratio to its lowest terms.

        What is ratio scaling and when is it useful?

        Scaling a ratio means multiplying both parts by the same factor to create an equivalent, larger (or smaller) ratio. For instance, scaling 2 : 5 by a factor of 3 gives 6 : 15. This is extremely useful for recipes (tripling a recipe), construction (scaling blueprints), mixing solutions, or any scenario where you need to maintain the same proportion at a different magnitude.

        What's the difference between a ratio and a fraction?

        A ratio A : B compares two quantities to each other (part-to-part), while a fraction A/B typically represents a part-to-whole relationship. However, any ratio can be expressed as a fraction: 3 : 4 is equivalent to 3/4 = 0.75. The key difference is context — ratios compare quantities side-by-side, while fractions represent a portion of a total.