The biggest laundry mistake people make: too much detergent
Most people use 2–4× more detergent than they should. Here's why that's worse than using too little — and exactly how much to actually use.
If your clothes feel scratchy, look dingy, or come out smelling musty even when “clean” — you’re probably using way too much detergent. It’s the most common mistake we see, and the one easiest to fix.
How much is “too much”?
Look at the cap on your detergent bottle. The line marked “small load” is roughly half what most people pour in. Modern detergents are 2–3× more concentrated than they were 15 years ago, but most people still measure by eye.
For reference, here’s what’s actually needed:
- Liquid detergent (HE concentrated): 1.5–2 tablespoons for a normal load. About one-third of a Tide bottle cap.
- Pods: 1 pod for a normal load. 2 pods only for a 45 lb washer fully loaded.
- Powder: 1.5 tablespoons. One scoop is usually too much.
For our 20 lb washer, use even less: about 2/3 of a normal-load amount.
Why too much is worse than too little
This is counterintuitive: using extra detergent doesn’t make clothes cleaner. It actually makes them dirtier. Here’s why.
1. Excess detergent doesn’t rinse out
The washer’s rinse cycle is calibrated for a specific amount of soap. Extra soap stays in the fabric and re-deposits on the next wear. That’s the “scratchy” feeling and the dingy gray look.
2. Trapped detergent attracts bacteria
Soap residue holds moisture longer. Damp fabric + leftover soap = the perfect environment for the bacteria that cause “musty towel smell.” This is why old towels smell wet even after washing.
3. It clogs your washer
Excess soap leaves a buildup inside the washer drum and pipes. Eventually it causes mold, smell, and machine failures. (We service our machines obsessively, but the same physics applies to your washer at home.)
4. It actually hides dirt
Modern detergents work by surrounding dirt particles and lifting them off fabric. Too much soap creates competing micelles that prevent the dirt from being lifted. Less soap = better dirt removal. Sounds backwards, but it’s chemistry.
How to know if you’ve been overdoing it
Try this test on your towels: run them through a wash cycle with NO detergent at all. Just water, normal cycle.
If the water comes out sudsy — there’s still old detergent in the towels. That’s a sign you’ve been over-soaping. Some people need to do this 2–3 times to get fully back to a clean baseline.
After that, use the correct amount going forward, and the towels will smell fresh and feel softer within a few washes.
What about heavily soiled clothes?
For really dirty work clothes, sweaty workout gear, or kids’ clothes after a muddy day:
- Don’t add more detergent. It won’t help.
- Pre-treat the dirty spots with a little extra detergent dabbed directly on the stain.
- Use the heavy-duty cycle (longer wash time + extra agitation).
- Use warm water instead of cold for greasy or oily soil only.
Good detergents for laundromat use
You don’t need anything fancy. Any “HE” labeled detergent (high-efficiency, designed for front-loaders) works. Tide, Gain, Persil, Arm & Hammer, generic store brands — they’re all fine.
What to avoid:
- Non-HE detergents (they create too many suds in front-loaders, can damage seals)
- “Free and clear” if you’re already not using fabric softener — these often contain less detergent and you’ll be tempted to use more
- Old detergent that’s been sitting open for over a year — loses potency
If you forget detergent, we sell single-load packs at the kiosk for a couple of dollars. They’re correctly portioned, so you don’t have to think about it.
→ See machine sizes and prices → Or our wash temperature guide