Pressure Cooker FAQ: filling the pressure cooker

Pressure Cooker Capacity: Frequently Asked Questionsl

Your pressure cooker and dinner can be ruined with too much food or too little liquid.  Too much food could block the pressure valve while too little liquid can permanently damage the cooker’s metal, bakelite and silicone fittings.  Here’s everything you need to know to keep your pressure cooker on the level and dinner coming.

What is a pressure cooker’s maximum capacity?

There are two maximum pressure cooker capacities and they depend on the ingredients being used.

Pressure Cooker Maximum Fill Levels

Pressure Cookers should only be filled to half when cooking beans, rice & grains and two-thirds for everything else.

  • Max 1/2 Full for Beans, Rice, Grains, Dehydrated Foods and Fruit – These foods either expand during cooking or generate lots of foam (or both). Beans can swell to twice their size during cooking and some grains, even more.  They also generate lots of foam and bubbles – which climb up the sides of the cooker to spray out of the valves – plugging them up.  This class of ingredients should also be opened using Natural Release method – which avoids the foamy starchy, bubbly, goo from spraying out of the valve during the pressure release, too.
  • Max 2/3 Full for Everything Else – Foods that don’t generally get any larger during cooking, bubble or foam are in this category and this includes meats, vegetables, soups and stocks.

If your recipe has lots of different ingredients, say a soup with vegetables and some beans, then you can go up to 2/3 full but if you’re cooking only one primary ingredient, say a bean chili, then you should respect that ingredient’s maximum capacity – 1/2 full .

Pasta and Chickpea Minestrone

Pressure cooked pasta & chickpea minestrone is mainly chickpeas, and should not go above 1/2  full.

Why should I care about my pressure cooker’s maximum capacity?

A pressure cooker’s maximum capacity is, in fact, a safety feature. In order for a pressure cooker to receive UL rating their manual must contain text to this effect.

Excerpt of UL-136 Rating Guidelines for Pressure Cookers 2009, section 15 Important safeguards

Excerpt of UL-136 Rating Guidelines for Pressure Cookers 2009, section 15 Important Safeguards

Pressure cooker maximum capacities apply to all pressure cookers types (electric, jiggler, weight-modified and spring valves), shapes (pressure pans, stockpot- and braiser-type cookers), sizes (from 1 to 12L) and origins (Europe, Asia, America). That’s because all pressure cookers have valves and safety mechanisms placed in the lid.

The maximum capacity recommendations are in place to ensure neither food nor cooking liquid interfere with, or trigger, the safety systems located in the lid. The NUMBER ONE REASON for pressure cooker mishaps usually involves someone not familiar with pressure cooking filling the cooker beyond the cooker’s recommended maximum capacity – ultimately blocking the pressure release valve.

How can I figure out my pressure cooker’s maximum capacity?

Unfortunately, many pressure cookers do not have markings inside to delineate these maximums.  If your pressure cooker doesn’t, fill up the cooker with water to get a visual feel for the location. For example, my un-marked 6L Fagor Futuro is 2/3 full when the water is just under where the handles attach and 1/2 full just above where the round bottom starts to go straight.

Here’s a handy chart that lists the most common pressure cooker sizes, and how much a pressure cooker can hold at each maximum capacity.

Pressure Cooker Size and Capacity Chart

Pressure Cooker SizeMax 2/3 Full Capacity
 Max 1/2 Full capacity
(all other ingredients)(beans, rice, grains & fruit)
(cup equivalent)
1 (4).662 1/2.052
1.5 (6)14.753
2 (8)1.3514
2.5 (10)1.66 1/21.255
3 (12)281.56
3.5 (14)2.391.757
4 (16)2.61028
4.5 (18)3122.259
5 (20)3.33132.510
5.5 (22)3.66142.7511
6 (24)416312
6.5 (26)4.33173.2513
7 (28)4.66183.514
7.5 (30)5203.7515
8 (32)5.3321416
8.5 (34)5.66224.2517
9 (36)6244.518
10 (40)6.6626520
11 (44)7.33295.522
12 (48)832624
Liters and quarts are used interchangeably by pressure cooker manufacturers. So when you purchase a 6 quart pressure cooker if it's made in the U.S. the cooker is exactly 6 quarts capacity, but if it's made in Europe or China, even if the size is stated in quarts, the pressure cooker is really 6L (which is actually 6.34 quarts).

Cups are roughly equivalent to 250ml, they rounded down to the nearest cup measurement in the maximum capacity calculations. Whether your pressure cooker is measured in quarts or liters the max-fill calculations in U.S. cups will work.

If your pressure cooker size is not listed above, simply multiply its size by .5 to calculate the cooker’s 1/2 capacity and .66 to calculate 2/3 capacity.

This is getting too technical, just tell me how much rice, beans or stock I can make in my pressure cooker!

For someone shopping for their first or second pressure cooker – the prime concern is how much food it will hold. Here is a table that describes the maximum capacity of some key representative ingredients. Remember that “Max” refers to both the ingredients and their cooking liquid.

Pressure Cooker Max Fill by Ingredient

Pressure Cooker SizeMax Soup/StockMax Dry Rice*Max Beans*
1 2 1/2 cups (500ml)1/2 cup (125ml)1/4 cup (30ml)
1.5 4 cups (1L)1 cup (250ml)1/2 cup (125ml)
25 1/4 cups (1.25L)1 1/4 cups (300ml)3/4 cup (180ml)
2.56 1/2 cups (1.5L)1 1/2 cups (375ml)1 cup (250ml)
38 cups (2L)2 cups (500ml)1 1/8 cups (265ml)
3.59 cups (2.25L)2 1/4 cups (530ml)1 1/4 cups (280ml)
410 1/2 cups (2.5L)2 1/2 cups (625ml)1 1/2 cups (375ml)
4.511 3/4 cups (3L)3 cups (750ml)1 3/4 cups (430ml)
513 cups (3.25L)3 1/4 cups (780ml)2 cups (500ml)
5.514 1/2 cups (3.5L)3 1/2 cups (875ml)2 1/8 cups (515ml)
615 3/4 cups (4L)4 cups (1L)2 1/4 cups (530ml)
6.517 (4.25L)4 1/4 cups (1L)2 1/2 cups (625ml)
718 1/4 cups (4.5L)4 1/2 cups (1.125L)2 3/4 cups (680ml)
7.519 3/4 cups (4.75L)5 cups (1.250L)3 cups (750ml)
821 cups (5.25L)5 1/4 cups (1.28L)3 1/8 cups (765ml)
8.522 1/4 cups (5.5L)5 1/2 cups (1.375L)3 1/4 cups
923 3/4 cups (6L)6 cups (1.5L)3 1/2 cup (780ml)
1026 1/4 cups (6.5L)6 1/2 cups (1.625L)4 cups (1L)
1129 cups (7.25L)7 1/4 cups (1.780L)4 1/4 cups (1.3L)
1231 1/2 cups (8L)8 cups (2L)4 1/2 cups (1.125L)
Measurements are rounded down to the nearest sensible/usable cup or liter quantity.
One cup is roughly equivalent to the the dry ingredient reaching 250ml in a measuring pitcher (sorry we cannot give the quantities in grams as beans and rice differ in their weight between varieties).
*assumes no more than two cups (500ml) of liquid per cup of dry rice
**assumes no more than 4 cups (1L) of liquid per cup of dry beans OR no more than 2 cups 500ml) of liquid for one dry cup of soaked beans

Is there a minimum pressure cooker capacity?

inside_pressure_cooker_measuring_scale_aEvery pressure cooker needs a minimum amount of liquid to generate enough steam to pressurize the cooker. Each manufacturer has their own minimum liquid requirements – this minimum is calculated based on the size of the pressure cooker, type of pressure valve and, for cookers that must vent to maintain pressure, cooking time.

A larger pressure cooker will need more steam to pressurize and will also need more liquid to boil and generate that steam.  Some pressure valves vent by function or design. While a spring valve releases little or no steam to keep a cooker at pressure, instead, a weight-modified or jiggler-type  valve must release pressure and steam rhythmically to maintain a set pressure. The extra venting means that a longer cooking time will evaporate more liquid, and the cooker will require more to keep it from running dry.

Some pressure cookers have a “min” line etched inside the cooker to make it easy to see if you’ve got enough liquid in them while others (usually the ones requiring more liquid) have a line with a 1/3 mark to indicate the minimum food and liquid requirement.

Refer to your pressure cooker’s manual to find its the minimum requirement.

Minimum liquid requirements excerpted from the manuals of Fagor, Silit and Fissler.

Minimum liquid requirements excerpted from the manuals of Fagor, Silit and Fissler (click to enlarge).

Can I use something other than water to reach my pressure cooker’s minimum liquid requirement?

You can reach your pressure cooker’s minimum liquid requirement with stock, fruit juice,  a little wine or beer –  but not hard liquor (large quantities of  alcohol will evaporate through the valve and the vapor will ignite).

Using advanced pressure cooking techniques you can calculate the liquid released by a vegetable or piece or meat in a recipe during pressure cooking – and use those liquids maintain pressure.  Here’s a handy chart that will get you half-way there .This technique has enough caveats  to merit its own article – so I won’t explain it here. Any well-written pressure cooker recipe from a trusted source, will have already made these calculations to get the most flavor from the pressure cooker.

Vegetable Water Content Table

More Questions?

Leave a comment below, and we’ll do our best to find the answer.



Pressure Cooker Fill Levels