Dial in a pour over brew: enter your coffee dose and ratio, and get total water plus a four-stage pour plan with bloom, three main pours and an expected cup count.
One millilitre of water weighs one gram, so grams and millilitres are interchangeable here. A 1 : 15 ratio with 20 grams of coffee needs 300 ml of water in total.
Pour over coffee rewards precision more than almost any other brew method. The same beans can taste thin and sour or heavy and bitter depending on how much water meets how much coffee, and the difference between those two outcomes is often just a few grams. The Pour Over Ratio Calculator turns a coffee dose and a chosen ratio into total water and a four-stage pour plan, so the brew can be repeated exactly the next morning.
This page explains what the ratio means, how the bloom and the main pours divide the water, and how grind size, roast level and batch size interact with the ratio. The goal is not a single perfect recipe but a repeatable method that can be adjusted one variable at a time.
How to Use the Pour Over Ratio Calculator
Enter the coffee dose in grams and choose a ratio from the list, or enter a custom ratio in the same form. Choose a bloom multiplier, usually twice the dose, and press the calculate button. The result shows total water, the bloom pour, three main pours that share the remaining water equally, an expected cup count based on 250 millilitre servings, and a plain-language note on whether the brew will taste strong, balanced or lighter.
The pour plan is written as amounts rather than times because kettles and drippers differ. Pour the bloom, wait about 45 seconds while the bed degasses, then add the three main pours with short pauses between them, keeping the water level roughly steady. The total brew time for a single serving usually lands between two and a half and three and a half minutes.
What the Ratio Means
A pour over ratio is written as coffee to water, such as 1 to 15, and it means one gram of coffee for every 15 grams of water. Because one millilitre of water weighs one gram, the same numbers work in millilitres, so a 1 to 15 ratio with 20 grams of coffee needs 300 grams or 300 millilitres of water. A smaller second number means less water per gram of coffee and a stronger cup, while a larger second number means more water and a lighter cup.
The classic range runs from 1 to 14 for a strong cup through 1 to 16 for a balanced cup to 1 to 17 or 1 to 18 for a lighter, more tea-like cup. Ratios outside that range are possible but harder to control: below 1 to 13 the brew can taste heavy and under-extracted, and above 1 to 18 it can taste thin even with a fine grind. Starting at 1 to 15 and moving one step at a time is the most reliable way to find a personal preference.
- 1 : 14 gives a strong, full-bodied cup
- 1 : 15 is the classic starting point for most drippers
- 1 : 16 gives a balanced, sweet cup
- 1 : 17 gives a lighter, more delicate cup
- Ratios are coffee to water by weight, and water grams equal water millilitres
Worked Example: 20 Grams at 1 to 15
Take the most common home recipe: 20 grams of coffee at a 1 to 15 ratio. Total water is 20 times 15, which is 300 grams or 300 millilitres. With a bloom multiplier of two, the bloom pour is 40 grams, and the remaining 260 grams divide into three pours of about 86.7 grams each. At 250 millilitres per serving, the brew yields about 1.2 servings, which is one generous mug.
Scaling the same recipe is simple multiplication. Thirty grams at the same ratio needs 450 grams of water, with a 60 gram bloom and three pours of 130 grams each, and yields about 1.8 servings. Fifteen grams needs 225 grams of water, a 30 gram bloom and three pours of 65 grams each. Keeping the ratio fixed while changing the dose is the cleanest way to brew for different numbers of people.
The Bloom Pour
The bloom is the first pour, usually twice the coffee dose, left to sit for about 45 seconds before the main pours begin. Fresh coffee releases carbon dioxide when it first meets hot water, and the bed visibly swells and bubbles during this stage. Pouring the full amount of water at once would let that gas escape unevenly and channel the water through weak spots, so the bloom exists to let the gas out under gentle, even wetting.
The bloom multiplier is usually two, but very fresh coffee within a few days of roasting may need three times the dose to settle, while older coffee may bloom barely at all. If the bloom water drains through before the main pours start, the bed was probably too coarse or the pour was too aggressive. A calm bloom that holds its shape for the full 45 seconds is a good sign for the rest of the brew.
Pour Stages and Timing
After the bloom, the remaining water is added in stages rather than all at once, and the calculator divides it into three equal pours. Staged pouring keeps the slurry depth roughly steady, which keeps extraction even, and it gives the brewer natural pause points to check the drawdown speed. If the water level drops very fast, the grind is probably too coarse; if it sits high and drains slowly, the grind is probably too fine.
Total brew time is the other half of the picture. A single serving of 20 grams should usually finish between two and a half and three and a half minutes from the first pour to the last drip. A much faster brew tastes sour and thin because too little was extracted, while a much slower brew tastes bitter and dry because too much was extracted. Adjusting grind size moves brew time more directly than adjusting the ratio does.
Grind Size and Ratio Together
Ratio and grind size work as a pair, and changing one without the other causes confusion. A finer grind extracts more from the same water, so it pairs naturally with a slightly higher ratio, while a coarser grind extracts less and pairs with a slightly lower ratio. When a brew tastes wrong, changing only one variable and tasting again is the only way to learn which one was at fault.
A medium grind, about the texture of coarse sand or raw sugar, suits most pour over drippers at a 1 to 15 or 1 to 16 ratio. A dripper with a slower drawdown, such as one with a small single hole, may need a slightly coarser grind to finish on time, while a fast dripper may need a slightly finer grind. The calculator fixes the ratio side of the equation so the grind can be tuned against a known target.
Choosing a Ratio for Light and Dark Roasts
Light roasts are dense and less soluble, so they usually taste best at a slightly lower ratio, around 1 to 14 or 1 to 15, with water near boiling and a finer grind. The extra coffee and hotter water compensate for the beans giving up their flavour reluctantly. Dark roasts are more soluble and more bitter, so they usually taste best at a slightly higher ratio, around 1 to 16 or 1 to 17, with water a few degrees cooler.
These are starting points rather than rules, and the same coffee can taste different at different ratios on different days. The useful habit is to record the dose, ratio, grind setting and water temperature for every brew that tastes good, so a great cup can be repeated instead of remembered vaguely. The calculator makes the dose and water side of that record automatic.
Scaling Up: One Cup Versus a Pot
Scaling a pour over recipe is not perfectly linear, because a larger bed of coffee drains more slowly and extracts more from the same ratio. A recipe that works at 20 grams may taste slightly stronger at 40 grams with the same ratio, and many brewers raise the ratio by one step when doubling, moving from 1 to 15 to 1 to 16. The calculator keeps the arithmetic exact, and the brewer adjusts taste from there.
Batch size also changes the pour plan in practice. A single serving suits three or four small pours, while a large batch may need five or six pours to keep the slurry depth manageable. The four-stage plan from the calculator is a solid default for one or two servings, and larger batches can split the main pours further while keeping the same total water.
Water Quality and Temperature
Water makes up more than 98 percent of a cup of coffee, so its quality matters as much as the ratio. Very hard water dulls acidity and can taste chalky, while distilled water with no minerals tastes flat and extracts poorly. Most brewers get good results with filtered tap water of moderate hardness, and some use a simple mineral recipe to reach a known baseline.
Temperature works with the ratio in the same way grind does. Water between 92 and 96 degrees Celsius suits most pour over brewing, with the hotter end for light roasts and the cooler end for dark roasts. Boiling water straight off the kettle is fine for very light roasts but can push darker coffee into bitterness, so a short rest after boiling is worth the wait.
Common Pour Over Mistakes
The most common mistake is measuring coffee by volume instead of weight. A scoop of light, dense beans can weigh several grams more or less than a scoop of large, airy beans, so two scoops are rarely the same dose. A scale accurate to a gram removes this entire category of error and is the single most useful purchase for pour over brewing.
The second mistake is pouring all the water at once, which floods the bed, channels through weak spots and finishes far too fast. The third is ignoring drawdown time entirely and judging the brew only by the recipe numbers. Recipe, grind and time form a triangle, and the calculator fixes the recipe corner so the other two can be judged honestly.
V60, Chemex and Other Drippers
Different drippers change drawdown speed and therefore change how a ratio behaves. A V60 with its large single hole and spiral ribs drains fast and suits a slightly finer grind, while a flat-bottom dripper with small holes drains more slowly and suits a slightly coarser grind. Thick paper filters slow the drawdown further and can mute acidity, while thin filters or metal filters let more oils through and give a heavier body.
The ratio arithmetic does not change between drippers, which is why the calculator stays useful across all of them. What changes is the grind and the pour rhythm needed to hit the target brew time. A recipe that finishes in three minutes in one dripper and four minutes in another needs a grind adjustment, not a ratio adjustment, and recognising that distinction saves a lot of wasted coffee.
Frequently Asked Questions
What is a good pour over ratio for beginners?
A ratio of 1 to 15 is the best starting point for beginners. It gives a balanced cup with most beans and most drippers, and it leaves room to move stronger toward 1 to 14 or lighter toward 1 to 16 after tasting.
How much water do I need for 20 grams of coffee?
At a 1 to 15 ratio, 20 grams of coffee needs 300 grams or 300 millilitres of water. The calculation is simply the dose multiplied by the second number of the ratio.
What is the bloom in pour over coffee?
The bloom is the first pour, usually twice the coffee dose, left for about 45 seconds. It lets trapped carbon dioxide escape so the main pours extract evenly instead of channelling through the bed.
How much water should the bloom pour be?
The bloom is usually two times the coffee dose, so 40 grams of water for 20 grams of coffee. Very fresh coffee may need three times the dose, while older coffee may barely bloom at all.
What grind size works for pour over?
A medium grind, about like coarse sand or raw sugar, suits most pour over drippers. Adjust finer if the brew finishes too fast and tastes sour, or coarser if it finishes too slowly and tastes bitter.
How long should a pour over brew take?
A single serving of about 20 grams should usually finish between two and a half and three and a half minutes from the first pour to the last drip. Larger batches take longer, and the time matters as much as the recipe.
Does a higher ratio mean stronger coffee?
No. A higher second number means more water per gram of coffee, which gives a lighter cup. A ratio of 1 to 17 is lighter than 1 to 14, even though the number is larger.
Can I use volume instead of weight for pour over?
Weight is far more reliable than volume, because the same scoop can hold different weights of different beans. A scale accurate to one gram removes the largest source of inconsistency in pour over brewing.
What water temperature is best for pour over?
Water between 92 and 96 degrees Celsius suits most pour over brewing. Use the hotter end for light roasts and the cooler end for dark roasts, which extract more easily and turn bitter sooner.
How do I scale a pour over recipe for two people?
Double the dose and double the water while keeping the ratio, then taste. Larger beds extract slightly more, so many brewers raise the ratio by one step when doubling, for example from 1 to 15 to 1 to 16.
Why does my pour over taste sour?
Sourness usually means under-extraction: the water was too cool, the grind was too coarse, or the brew finished too fast. Try a finer grind or hotter water before changing the ratio.
Why does my pour over taste bitter?
Bitterness usually means over-extraction: the water was too hot, the grind was too fine, or the brew took too long. Try a coarser grind or slightly cooler water before changing the ratio.
Do I need a gooseneck kettle for pour over?
A gooseneck kettle helps control the pour, which keeps agitation even and the slurry level steady. It is helpful but not essential, and careful pouring from any kettle beats careless pouring from a gooseneck.
How is pour over different from a Chemex brew?
A Chemex is a type of pour over dripper with very thick filters and a larger body, so it drains more slowly and gives a cleaner, lighter cup. The ratio arithmetic is identical, but grind and pour rhythm adjust to the slower drawdown.
How many cups does a 20 gram pour over make?
At a 1 to 15 ratio, 20 grams of coffee makes 300 millilitres of brewed coffee, which is about 1.2 servings of 250 millilitres, or one generous mug.