What size washing machine do I need for my household

How to work out the washing machine size

The capacity comes from your weekly laundry divided by the number of washes, with a margin because the drum is not always full. The starting figure is European: according to the European Environment Agency (EEA), each person washed 270 kg of laundry in 2020, which is 5.2 kg (about 11 lb) a week. If your household washes more or less, change it in the advanced options.

Weekly laundry divided by washes gives the average load. The number on the machine, though, is the rated capacity: EU Regulation 2019/2014 defines it as the maximum weight of dry textiles the maker declares for one cycle, measured on the eco 40-60 cotton programme. At home the drum is often not full, because whites, colours and delicates go in separate loads. The same regulation tests every machine at full, half and quarter load and weights the three results with factors that depend on capacity: for an 8 kg machine the resulting average load is 60% of the drum. The calculator divides the average load by 0.60 to get the minimum capacity.

In the UK and Europe the size to buy is the first one on sale that covers it (6, 7, 8, 9, 10, 11 or 12 kg). If you wash duvets at home, Samsung gives at least 9 kg for a double and 10 to 12 kg for a king size; the calculator takes 10. Front-loading machines are 60 cm wide and 85 cm high, and the depth grows with the capacity.

In the US washers are sold by tub volume in cubic feet. To turn pounds into cubic feet the calculator uses the DOE test load table: the maximum test load grows by 4.1 lb for every cubic foot, plus 0.2 lb (3.0 cu ft takes 12.5 lb, 4.5 cu ft takes 18.7 lb). In the same table the average load at 4.5 cu ft is 10.85 lb, 58% of the maximum, close to the European 60%. Consumer Reports finds that a king comforter needs at least 4.5 cu ft; it is the only figure published, so the calculator uses it for a queen comforter as well, on the safe side.

Worked example: three people in the UK, four in the US

With the values the calculator opens with in metric units: three people, four washes a week, no duvet, a 60 × 60 cm space 85 cm high.

• Laundry: 3 × 5.2 = 15.6 kg a week
• Average load: 15.6 ÷ 4 = 3.9 kg per wash
• Minimum capacity: 3.9 ÷ 0.60 = 6.5 kg

The calculator gives a 7 kg washing machine, filled to 56% by the average load. A 7 kg machine is 40 to 48 cm deep, so it fits the 60 cm space. A double duvet raises the size to 9 kg.

In US units the calculator opens with four people, six loads a week and a laundry closet 30" wide, 36" deep and 48" high:

• Laundry: 4 × 11 lb = 44 lb a week
• Average load: 44 ÷ 6 = 7.3 lb per load
• Full load needed: 7.3 ÷ 0.60 = 12.2 lb, which in the DOE table is a 2.9 cu ft tub

Full-size washers start at 3.2 cu ft, so the calculator gives a 3.2 cu ft washer. A top-loader (26-29" deep, 42-46" high) fits with the 6" Consumer Reports asks for behind it; a front-loader (27-35" deep) fits or not depending on the model. With a king comforter the size rises to 4.5 cu ft.

Washing machine size by household

Size to buy with 5.2 kg of laundry per person and the drum 60% full on average, no duvets:

People	3 washes	4 washes	5 washes
1 or 2	6 kg	6 kg	6 kg
3	9 kg	7 kg	6 kg
4	12 kg	9 kg	7 kg
5	over 12 kg	11 kg	9 kg
6	over 12 kg	over 12 kg	11 kg

The same in the US, with 11 lb per person:

People	4 loads	6 loads	8 loads
3	3.4 cu ft	3.2 cu ft	3.2 cu ft
4	4.5 cu ft	3.2 cu ft	3.2 cu ft
5	5.6 cu ft	3.7 cu ft	3.2 cu ft
6	over 5.8 cu ft	4.5 cu ft	3.4 cu ft

The number of washes matters more than the number of people: two people washing twice a week need a 9 kg machine, the same as four people washing four times. Where the table says "over", add a wash a week.

Sizes on sale: slimline, standard, large and US washers

Samsung's guide gives the same width (600 mm) and height (850 mm) for front-loaders up to 12 kg; the depth changes:

• 6-7 kg (slimline): up to 480 mm deep, the thinnest 400 mm;
• 8-10 kg: 550 to 600 mm;
• 11-12 kg: 600 to 650 mm.

Above 13 kg all three measurements change and the machine often no longer fits under a worktop. Between the smallest and the largest depth of a class the calculator says "depends on the model": check the data sheet before you buy. These are machine sizes; the room behind for the hoses is in the installation manual.

In the US, Consumer Reports tests full-size washers from 3.2 to 5.8 cu ft, about 27" wide, and compacts up to 2.8 cu ft, about 24" wide, and asks for at least 6" behind the washer for the water hookups. Samsung gives front-loaders 33-39" high and 27-35" deep, top-loaders 27-28" wide, 42-46" high and 26-29" deep.

Common mistakes

• Reading the capacity as the load of every wash. The kilograms on the label are for cotton on the eco 40-60 programme; every other programme has its own maximum, given in the manual.
• Measuring only the width. Front-loaders are all 60 cm wide in Europe: the depth decides whether a 9 kg machine fits.
• Buying the biggest "just in case". EEA data show machines used at 53% of their capacity in 2020: 4 kg per wash in drums of 7.6 kg on average.
• Forgetting the duvet. A double needs at least 9 kg, a king comforter 4.5 cu ft; if the space does not allow it, the duvet goes to the laundromat.
• Weighing wet laundry. Capacity is always the weight of dry fabric.