How Much Laundry Detergent Should I Use?

If you do laundry, you are almost certainly doing it wrong. But you are not alone, because almost everyone who does laundry is making the same laundry mistake: Using too much laundry detergent.

This happens, in large part, because laundry detergent doses are notoriously indecipherable. They're based on a nebulous and ill-defined idea of "load size" and expressed by difficult-to-see fill lines on detergent bottle caps, leading users to dump what feels like the right amount into the machine and hope for the best.

Then there is psychology—the "what feels right" part of the equation. We might feel the urge to use more laundry detergent than is actually needed because something in our brain signals to us that "more detergent equals more clean." Unfortunately, not only is that not the case—the opposite is true. Leaving clothes and household goods like sheets and towels full of suds makes them decidedly less clean. 

So what is the right amount of laundry detergent to use? And does it really matter? This guide breaks down the reasons precise dosing is important, how to determine the size of a load of laundry, and how much detergent to use to ensure your laundry is as clean as can be.

Why Correct Laundry Detergent Dosing Matters

Using too much laundry detergent can drain your bank account, ruin your clothes, cause you to break out in a rash, and shorten the lifespan of your washing machine. Does that sound dramatic? Perhaps a bit! But it got your attention, didn't it? And it's all true. 

The most straightforward reason to practice precise laundry detergent dosing is one of cost; simply put, overusing detergent means you'll need to buy more of it than you actually need to keep your clothes and household goods clean.

Then there is the appearance of your clothing: Residue from detergent will lend clothes, as well as household linens like sheets and towels, a dingy appearance. 

All that excess detergent lending a dingy appearance to your clothes can, and very frequently does, lead to another very common side effect—skin and respiratory irritation. Soap residue in clothes, towels, and especially sheets, can lead to skin irritation and rashes, and can exacerbate skin conditions like eczema and psoriasis. And, with towels in particular, lingering excess soap can cause a sour, mildew smell to develop.

And, finally, excess detergent will build up in your washing machine over time, clogging the compartments, hoses, and valves, leaving laundry less clean and the machine susceptible to mold, and shortening the lifespan of the appliance.

How to Determine Load Size

The correct detergent dosage depends entirely on the size of the load of laundry, which can turn laundry day into a frustrating guessing game. Unfortunately, determining what constitutes a medium load of laundry versus a large load of laundry is an imprecise science, but there are a few (imperfect) methods that can help you figure out what size load you're working with.

The Approximate Weight Method

The approximate weight method relies on the weight of the load of laundry to determine its size.

• Medium load: Approximately 6 pounds
• Large load: Approximately 11 pounds
• Extra-large load: Approximately 21 pounds

The Armload Method

The armload method is one in which the load size is approximated based on how much of the load you can carry in one arm.

• Medium load: Less than a full armload
• Large load: A full armload
• Extra-large load: More than a full armload

Drum Fullness

Use the fullness of the washer's drum, when loaded with dirty laundry, to assess the load size.

• Medium load: The drum is half full
• Large load: The drum is three-quarters full
• Extra-large load: The drum is full, but not packed tightly

The Eyeball Method

The eyeball method measures load size in the number and type of items being washed in a load.

• Medium load: Approximately 6 adult t-shirts, 2 adult sweaters, 3 pairs of pants, 2 skirts, 3 pairs of underwear, 3 pair of socks 
• Large load: Approximately 12 adult t-shirts, 2 adult sweaters, 5 pairs of pants, 3 skirts, 4 pairs of underwear, 6 pairs of socks
• Extra-large load: 12 adult t-shirts, 12 pairs of socks, 6 skirts, 15 adult sweaters, 6 pairs of pants and 6 pairs of underwear

How Much Liquid Laundry Detergent to Use

Once you've determined the load size, you will be able to measure the correct dose of liquid laundry detergent, either using the fill lines on the cap or by measuring it in tablespoons using the chart below. When washing heavily soiled items, use slightly more detergent than the recommended dose. Handwashing calls for less detergent than machine washing; dilute 1 to 2 tablespoons of liquid detergent in water to make a solution for a small load of handwashing (less than 5 pounds, or approximately 2 to 5 items of clothing).

• Medium load: Approximately 3 tablespoons of liquid laundry detergent
• Large load: 4 to 5 tablespoons of liquid laundry detergent
• Extra-large loads: 8 tablespoons of liquid laundry detergent

How Many Detergent Packs to Use

Detergent packs or pods are pre-measured based on a medium load size. Detergent packs allow for less control over dosing, and should never be punctured for use in hand laundering. 

• Medium load: Use 1 detergent pack
• Large to extra-large load: Use 2 detergent packs
• XX-Large loads: Use 3 detergent packs