How to Make French Press Coffee: Ratio and Size Guide

A useful French press coffee ratio is 1:15 by weight: 1 g of dry coffee for every 15 g of brewing water. For a manageable first batch, weigh 30 g coffee and 450 g water. Keep those quantities steady while you learn your grinder and press, then change one thing at a time.

Use the charts below to choose a batch for your press, follow the four-minute method, then adjust the next brew to taste.

How this guide was prepared: Coffee Corner researched manufacturer instructions and roaster recipes. We have not brewed or tested the equipment for this article. The images are AI illustrations, not records of a tasting or equipment test.

The starting recipe: 30 g coffee and 450 g water

• Coffee: 30 g, freshly ground to the coarse setting recommended for your press.
• Water: 450 g hot drinking water, around 205°F / 96°C unless your press specifies otherwise.
• Ratio: 1:15, measured before brewing.
• Steep: approximately four minutes as a starting point, followed by a slow, gentle press.
• Vessel: a press large enough to hold the water, grounds and the headroom its instructions require.
• Serve: pour promptly after pressing; expect less finished drink than the water you added.

The rounded ratio and staged pour adapt Stumptown's recipe: 56 g coffee with 850 g water, approximately 1:15.2. Our 30 g / 450 g quantities are an adaptation, not its exact formula.

The National Coffee Association's method independently supports weighing, a coarse starting grind, roughly four minutes and gentle plunging. Its published ratio range also includes 1:15.

What 1:15 means, and how to calculate it

Always write the coffee amount first. At 1:15, 20 g coffee takes 300 g water; 40 g takes 600 g. Multiplying both ingredients by the same number changes the batch size while keeping the proportion unchanged.

To find the dose for a chosen water amount, divide the water weight by the ratio's second number. For 500 g water at 1:15, calculate 500 ÷ 15 = 33.3 g coffee. A scale that reads whole grams can use 33 g; the actual ratio is then about 1:15.15. Whole-gram rounding is sufficient for this recipe.

Work the other way if you have a fixed amount of beans: multiply coffee weight by the ratio number. The 24 g left in a bag makes a 360 g water recipe at 1:15. If the vessel cannot safely accommodate that batch, reduce both ingredients together or brew in a larger press.

A smaller second number means more coffee for the same water: 1:12 is a heavier dose than 1:15, while 1:17 is lighter. A lower ratio number makes a more concentrated starting recipe; grind and brewing time still affect the flavor. Use the brew ratio calculator for a quantity not shown below.

French press ratio chart

Each row starts with the water you intend to add. Coffee doses are rounded to the nearest gram. The chart is a calculation aid; it is not a set of manufacturer-approved maximum fill levels.

For example, moving a 450 g water batch from 1:15 to 1:17 changes the coffee dose from 30 g to about 26 g. Keep the water, grind and timing the same for that comparison. Moving to 1:12 raises the dose to about 38 g; check that the extra grounds still leave adequate room.

If you add milk, count it separately. Brewing 30 g coffee with 450 g water and later adding 60 g milk does not make the brewing ratio 1:17. The brewing ratio remains 1:15; the serving has changed. Keep both numbers in your notes if milk is part of your everyday cup.

Keep ounces labeled too. Fluid ounces on a measuring jug describe volume; ounces on a scale describe weight. Do not divide a fluid-ounce water measurement by 15 and treat the answer as ounces of coffee. The easiest way to avoid the mismatch is to switch the scale to grams and use grams for both ingredients throughout the recipe.

Choose a batch that fits your French press

Beware of the word “cup.” The Bodum Brazil listing calls its 34 oz model an eight-cup press. Those are small coffee servings, not eight US measuring cups. Using NIST's approximate conversion, 34 US fluid ounces is about 1,005 mL; eight eight-fluid-ounce measuring cups would be about 1,893 mL. Neither number tells you the finished yield of a recipe.

A press's advertised capacity and your recipe water are different numbers. Grounds occupy space, and safe use requires headroom. A vessel labeled 1 liter should not automatically receive 1,000 g water plus coffee. Read its fill guidance before choosing the largest row in the chart.

For recipe planning, grams of water are approximately milliliters. Weighing both ingredients avoids confusion between vessel markings, measuring cups and mugs.

Starting doses by advertised press size

This planning table leaves roughly 20% of the nominal vessel volume for grounds and headroom. That is an allowance for estimating a batch, not a safe-fill rule or a manufacturer-approved recipe. Your press's fill line, required headroom and minimum brew size take priority; reduce the water if needed and divide the new water weight by 15.

The milliliter capacities above are rounded: 12 US fl oz converts to about 355 mL, for example. Water is calculated from the rounded metric capacity × 0.8; coffee is water ÷ 15, rounded to the nearest gram. The water column is the amount added before brewing, not the finished drink yield. A 34 oz press can also brew the smaller 450 g / 30 g recipe, provided its instructions allow that fill level.

Plan around the actual mugs you use. If you want two 200 mL servings, 400 g brewing water will not provide a reliable 400 mL finished yield: some liquid stays with the grounds. Allow a margin without assuming a fixed retention amount. Measure the drink you pour once, then adjust the next batch proportionally within your press's limits.

Do not solve a short serving by pouring additional water into the spent grounds and treating that as the same recipe. You have introduced another brewing step. If the coffee in the mug is stronger than you want, adding a little hot water directly to the finished drink is a clearer adjustment.

For three people, decide whether you can brew one adequate batch safely. Use two smaller batches if one will exceed the fill limit.

How to brew the 30 g / 450 g batch

Set out a clean press, scale, timer, kettle, suitable stirring utensil and serving vessel. Read your press's assembly and fill instructions first. A kitchen scale that reads in grams is enough.

For timing and handling, the OXO general guide supports starting the four-minute timer at the first pour and pressing slowly. Manufacturer safety instructions take priority throughout.

1. Check and prepare the press. Set it on a stable, heatproof surface. Inspect a glass beaker for damage. Preheat if the maker permits, then discard all rinse water.
2. Weigh the coffee. Tare an empty bowl, weigh 30 g beans and grind. Add the grounds to the press. Place the press on the scale and tare again, so its next reading measures water alone.
3. Begin the brew. Start the timer with the first pour. Add about 225 g hot water and wet the grounds evenly.
4. Complete the water at one minute. Stir gently to wet remaining dry pockets, then pour to 450 g total on the scale. That means approximately another 225 g, not another 450 g. Fit the lid as your model directs, with the plunger raised.
5. Press at four minutes from the first pour. Move the press off the scale onto the stable surface. Hold it securely and lower the plunger slowly, without force. Stop if it jams; follow the manufacturer's obstruction instructions.
6. Pour and serve. Decant the coffee you intend to drink into mugs or a separate vessel. Leave the muddy last portion behind if you dislike sediment.

Safety details vary. The Bodum Brazil manual calls for nonboiling water, at least one inch of headroom, a plastic stirring utensil and gentle pressure with the spout turned away. It prohibits stovetop use. Apply your model's instructions rather than copying the fill level or handling shown for another press.

If you accidentally overshoot the water, write down the actual quantity. With 30 g coffee and 480 g water, you brewed at 1:16. You can still assess the cup, but label the result correctly before using it to decide your next adjustment.

Keep grind, temperature and timing repeatable

Begin with the coarse grind specified by your maker. The National Coffee Association's guide recommends coarse grounds and a burr grinder for more uniform grinding. “Coarse” is still a starting description: record the setting on your own grinder so you can reproduce it.

Numbers do not transfer between grinders. For example, the original Baratza Encore manual suggests setting 28 for French press, then says the actual setting needs adjustment. That is not an instruction for an Encore ESP or another brand. If buying a grinder, our grinder guide explains the choices; you do not need to replace equipment before measuring a first batch.

A kettle reading and the temperature inside the press are different things. Barista Hustle's temperature experiments show why vessel and batch size affect heat loss. Record the kettle setting rather than assuming a fixed wait after boiling works in every kitchen. Keep any preheating routine consistent and stay within your press's instructions.

Four minutes is a starting point for this method. Barista Hustle also describes a longer method that includes settling time. Try a complete alternative method separately; mixing its timing into this recipe makes the comparison harder to interpret.

Change strength without chasing every variable

Strength describes how concentrated the drink is. Extraction concerns what the water takes from the grounds. Bitterness, sourness, heaviness and grit are observations you can make; none is a complete diagnosis by itself. A thin cup can also be unpleasantly bitter, so adding more coffee is not automatically the answer.

If the flavor is pleasant but too concentrated, add a small, measured amount of hot water to the finished cup. Try 10 g at a time and note the amount you prefer. That lets you explore dilution without changing the brew. For the next batch, you can compare a slightly lighter dose at the same brewing-water weight.

If the cup tastes diluted, first check the numbers. Did you tare after adding the grounds? Did the second pour accidentally add the full water amount again? Did milk or extra serving water change the drink? Correct a measurement mistake before changing grind, time and dose together.

There is no universal winning ratio. Blue Bottle's recipe uses 30 g coffee with 350 g water, about 1:11.7. The OXO GroundsLifter recipe card specifies 52 g for 946 mL, approximately 1:18.2. These are different starting recipes for different preferences and workflows, not proof that either is wrong.

For a simple comparison across mornings, keep 450 g water as the constant. Brew 30 g coffee first, then try 28 g if you want a lighter dose or 32 g if you want a heavier one. Those alternatives are about 1:16.1 and 1:14.1. Keep the same bag, grind, timing and serving additions. Keep the version you prefer before changing another variable.

Troubleshoot the next batch, one change at a time

There is grit at the bottom

Some sediment is expected with metal filtration. OXO's brewing guide explains that mesh leaves more fine particles than paper. Check that the filter is assembled correctly, pour gently and leave the last muddy mouthful in the press. If the grounds contain obvious powder, investigate the grind before increasing the coffee dose. A higher dose does not repair a damaged or poorly seated filter.

The plunger is difficult to push

Stop rather than leaning harder on it. Let the manufacturer's instructions determine what to do next; hot liquid under pressure is not a useful taste experiment. Check the supported grind and filter assembly before brewing again. Specialized presses can feel different: ESPRO's guide uses a linked dual-filter assembly and model-specific fill lines. Do not insert a paper filter into an ordinary press because another brand supports one.

The cup is weak, sharp, bitter or flat

Write down the dominant problem in plain language. For a weak cup, confirm dose and total water first. For a harsh cup, check cleanliness and compare the same coffee with a modest dilution. For a sharp or flat cup, check the recorded water temperature, timing and beans before selecting one change for the next brew. Our coffee troubleshooting guide covers other possible causes.

A useful note is specific: “30 g, 450 g, grinder setting 28 on my original Encore, four minutes, pleasant flavor but too concentrated; preferred 20 g serving water.” “Bad coffee” provides little direction. Keep the successful notes too, so the next bag does not erase what worked.

Clean the parts your model allows you to remove

Let the equipment cool enough to handle safely, remove the spent grounds and wash the beaker and filter after use. OXO recommends gentle soap and water followed by air drying. Follow your exact model's instructions for disassembly and dishwasher use. Do not force a bonded filter connection apart or remove a glass insert merely because a similar-looking model comes apart.

Inspect the filter before reassembly and check glass for damage. A clean setup also makes comparisons more useful: a new ratio should not have to compete with yesterday's residue. Our coffee-equipment cleaning guide separates washing from descaling and covers other brewers.

Common French press ratio questions

Can I use tablespoons instead of a scale?

Yes. For a no-scale starting point, OZO Coffee Roasters recommends 2 tablespoons of ground coffee for every 6 oz of water. The table scales that volume-based suggestion. It is an alternative starting recipe, not a conversion of our 1:15 weighed recipe.

Use a measuring tablespoon and keep how you fill it consistent. The roaster does not specify a universal gram weight per spoon. Roast, grind, spoon shape and heaping change the dose, so taste the result and adjust the next batch. The water amounts above are not press fill limits or finished drink yields; your manufacturer's headroom instructions still apply. When a scale is available, weighing both ingredients will make a preferred recipe easier to repeat.

Can I make one small cup in a large press?

Only if the batch meets that model's operating instructions and the filter works at that fill level. Scaling 15 g coffee to 225 g water preserves 1:15 mathematically; it does not change the height or travel of the plunger. Choose a press that suits your regular serving size rather than assuming every large vessel works equally well nearly empty.

Should I buy special French press beans?

Start with coffee you already enjoy and can identify, then record the bag and roast alongside your recipe. A label promising suitability for French press does not replace a dose measurement or grind instruction. Use the same bag for your first comparisons, and keep it stored consistently; our coffee storage guide covers the basics.

What should I change for tomorrow's cup?

If today's measured recipe tasted good, repeat it. If it did not, choose one problem and one adjustment. Keep the record short enough that you will actually use it: coffee, water, grinder setting, timer and one sentence about the cup. That turns a starting ratio into a recipe you can reproduce.