How to Calculate Washer Capacity and Laundry Load Size

Sizes formula and chart

How to Calculate Washer Capacity

The Spruce / Nusha Ashjaee

One of the key factors in ending up with truly clean laundry is to not overload the washer. Clothes need room to "swim" in the water and detergent solution during agitation to remove soil and stains. If the washer tub is jam-packed, some clothes will have limited exposure time to the cleaning solution and will come out with their original stains and odor. That's why it is important to know the capacity of the washer you are using so you don't overstuff. But how big is your washer drum and how much laundry can you safely put in the washer? 

If you have lost your washing machine manual and you need to know the capacity of your washer tub, it is simple to calculate. This is also helpful if you want to replace an older machine with one with the same washing capacity. Determining your washer's capacity will also help you know how many clothes it should hold in every load to get good results.

The Formula to Calculate Tub Capacity of a Washer 

Use this equation to calculate the volume or holding capacity of the washing machine tub; assuming all measurements are in feet.

Equation: Volume (cu. ft.) = pi × r × r × D


For the equation, follow this key:

  • pi = ~3.14
  • r = radius (feet); remember r = diameter divided by two
  • D = depth (feet); in classic geometrical terms the height of the cylinder
  • Note: The units result in (cu. ft.). ft × ft × ft = cubic feet.

How to Calculate the Tub Volume or Capacity of a Washer

  1. Make all measurements in feet.
  2. Measure the radius of the tub; from the center of the tub to the outside wall of the tub. Alternatively, measure the diameter and divide by two. This is the radius.
  3. Using the formula, multiply the radius by the radius; note this is not the same as multiplying the radius by two. This is equivalent to the radius squared.
  4. Multiply the radius squared from step three above by pi (3.14).
  5. Multiply the value from step four by the depth of the tub to find the cubic feet volume or capacity of the washer.
measuring the radius of a washer tub

The Spruce / Nanor Zinzalian

Load Capacity by Washer Size

If you are searching for a new washer, different styles are sold with the capacity listed in cubic feet. Now that you know the size of your washer drum, you can figure out how much laundry it will hold in each load. Remember, while it is economical in both utility costs and time management to do full loads, you should never cram clothes and overstuff a washer just because you can. Always check your manual to see specifics for your model washer, but here is a washing machine load size chart with average load capacities for various size washers.

Machine Type* Cubic Feet  Pounds of Laundry Per Load 
Compact 1.5 to 3.4 4 to 8
Standard 3.5 to 4.4 12 to 16
Large 4.5 to 5.0 16 to 20
Extra-Large 5.1 to 6.2 20 to 25

*Machine type applies to both top-loading and front-loading washing machines.

How Much Does Laundry Weigh?

When automatic washers became commonplace in homes in the 1950s and 1960s, the washer manufacturers began using the term "load of laundry." At that time, the capacity of most washers averaged 8 pounds of clothes or linens. As washers became larger so did the pound limits of "a load." The introduction of high-efficiency washers that contain no center agitator increased the load capacity. Front-loading high-efficiency washers rely on a tumbling action to move clothes through the cleaning solution and top-loading high-efficiency washers use a bottom paddle agitator leaving more space for dirty clothes.

To give you an idea of how much dirty laundry weighs, here are some guidelines:


Type Of Laundry

What It Weighs

XL T-shirt

.5 pounds

Medium Blue Jeans

1.6 pounds

Medium Sweatshirt

.9 pounds

One Full-Size Bed Sheet

1.3 pounds

One Large Bath Towel or Beach Towel

1.6 pounds

These weights give you a good guideline as to how many of each item can fit in a load of laundry. After you have sorted the laundry (as you always do, right?), you should weigh your empty laundry basket and then fill it with what you estimate as a full load of dirty clothes. Weigh the filled basket again and adjust appropriately. You may be able to wash more or you may need to remove some items. As an example, 12 pounds of laundry might look like a load of two bath towels, six T-shirts, and four pairs of jeans.

Now you're ready to load the washer and select the appropriate water temperature and cycle. If you have several members of the household doing laundry, take some photos of a full load or post the appropriate weights on a bulletin board. It might just give you cleaner clothes and help your washer last longer.

laundry load on a scale

The Spruce / Nanor Zinzalian