Short answer: use the dose printed for your water hardness and soil level, measured rather than poured, and adjust it for how full the drum actually is. One pod covers a normal full load; a half-empty drum needs less liquid, not the same amount. Overdosing does not clean better. It leaves residue in the fabric, which makes clothes stiff and grey, irritates skin, feeds the bacteria that cause the musty smell, and builds up inside the machine.
What a correct dose looks like
Treat the figures below as a starting point and adjust by one notch for your water. Most detergent caps have two or three fill lines on them, and the lowest line is the one that applies to a normal load in soft water — a fact that is easy to miss, because the cap is also the container and it is natural to fill it.
| Situation | Liquid | Pods | Powder |
|---|---|---|---|
| Full drum, normal soil, soft water | 35 to 40 ml | 1 | 70 g |
| Full drum, normal soil, hard water | 50 to 60 ml | 1, plus a water softener | 100 g |
| Half drum | 20 to 25 ml | 1 is the minimum; do not cut one open | 40 g |
| Heavily soiled, work or sports | 55 to 65 ml | 1, plus a pre-treat | 110 g |
| Towels and bedding at 60 °C | 50 ml | 1 | 100 g |
| Delicates, hand wash | 5 to 10 ml per 5 litres | Not suitable | Not suitable |
Pods are a fixed dose, which is their main advantage and their main limitation. They are correct for a full normal load and slightly generous for a small one, which is an argument for running full loads rather than for cutting pods open. Never do that: the film is there to control when the detergent releases. The full method is in how to use laundry pods.
The three things that change the dose
- How full the drum is. Detergent works on the water, and a half load holds roughly half the water. This is the variable people ignore most.
- How dirty the load is. Soil consumes surfactant. A week of office shirts needs noticeably less than a weekend of mud and sweat.
- Water hardness. Calcium and magnesium bind to surfactant before it reaches your clothes, so in a hard water area a normal dose behaves like a small one. The mechanism, and why adding more detergent is the wrong fix, is in the hard water guide.
What overdosing actually does
The intuition that more detergent means cleaner clothes is wrong in a specific way. A wash has a fixed volume of rinse water, and that water can only carry away so much. Past the correct dose, the surplus has nowhere to go, so it stays in the fabric and in the machine.
| Symptom | What is happening |
|---|---|
| Clothes feel stiff or waxy | Surfactant dried in the fibre. It is a coating, not a texture |
| Whites and pales going grey | Residue holding onto loosened soil instead of releasing it |
| Skin irritation, worst at night | Residue in bedding against skin for eight hours |
| Towels no longer absorbent | Coated fibres repelling water |
| Musty smell returning within a day | Residue is food for odour bacteria. See why clothes still smell |
| Dark clothes with white streaks | Undissolved detergent, usually powder in a cold wash |
| Excess foam, cycle running long | The machine detecting suds and adding rinses, which wastes water and time |
| Black slime in the drawer or door seal | Biofilm feeding on detergent build-up |
And what under-dosing does
It is the less common error but it is not harmless, and it looks different: clothes come out looking fine and smell sour within a day, because the soil was loosened but never fully carried away. Greying happens here too, gradually, as each wash leaves a little more behind. If you have cut your dose to be gentle on someone's skin and things now smell, the answer is a full dose plus an extra rinse, not a smaller dose.
How to reset
- Measure once, properly. Pour your usual amount into the cap, then compare it to the line you actually need. Most people are surprised.
- Strip what has built up. Two hot washes with no detergent and 120 ml of white vinegar clears residue from towels and bedding.
- Clean the machine. Empty 90 °C cycle, pull the drawer out and scrub it, wipe the door seal. See how to clean a washing machine.
- Drop to the correct dose and run normally for two weeks before judging the result. Residue takes a few washes to clear.
- Add one rinse if anyone in the house has sensitive skin, rather than cutting the dose.
- Keep a measure in the cupboard rather than using the cap by eye. The cap is designed to be easy to overfill.
Where fragrance fits
More detergent is not how you get clothes to smell better for longer, and it is the most common thing people try. Fragrance added to the wash water largely leaves with the rinse water, which is why a correct dose plus a scent step on the dry load outperforms a double dose every time. Our dryer sheets are that step, and the reasoning is set out in how to make laundry smell good for weeks.
Frequently asked questions
How much laundry detergent should you use per load?
About 35 to 40 ml of liquid, one pod, or 70 g of powder for a full drum with normal soil in soft water. Increase by roughly half in a hard water area or for heavily soiled loads, and halve the liquid or powder for a half-full drum. Measure it rather than filling the cap by eye.
What happens if you use too much laundry detergent?
The surplus cannot be rinsed away, so it stays in the fabric and the machine. Clothes come out stiff, whites go grey, towels stop absorbing, skin gets irritated and a musty smell returns within a day, because the residue feeds odour bacteria. It also causes excess foam, which makes the machine add rinses.
Does more detergent clean better?
No. A wash has a fixed volume of rinse water and it can only carry away a fixed amount of detergent. Past the correct dose you are adding something that will stay in the clothes. If a load is not coming out clean, the cause is usually a packed drum, a cold wash on greasy soil or hard water, not a small dose.
Should you use less detergent for a small load?
Yes, for liquid and powder: roughly half the dose for a half-full drum, because detergent acts on the water and a small load holds less of it. Pods are a fixed dose and cannot be split, so they suit full loads best. Never cut a pod open.
How do you know if you are using too much detergent?
Look for stiff or waxy fabric, towels that have stopped absorbing, white streaks on dark clothes, lots of foam through the door, a long cycle with extra rinses, and black residue in the drawer or door seal. Any two of those together mean the dose is high.
How much detergent for hard water?
Around half as much again as the soft water dose, or the same dose plus a dedicated water softener, which is the better option. Minerals in hard water bind to the surfactant before it reaches the clothes, so in a hard water area a normal dose behaves like a small one.
How do you remove detergent build-up from clothes?
Run two hot washes with no detergent at all and 120 ml of white vinegar in the drum, then wash normally at the correct dose. Expect it to take a few washes for towels to recover their absorbency fully, and clean the machine at the same time or the residue comes straight back.
