Wash your sheets and pillowcases once a week. That's the interval in Whirlpool's sheet-washing guide, and it's the same one allergy organizations give for dust mites. Wash more often if you sweat a lot at night, a pet sleeps on the bed, or someone has been sick. Two weeks is already a stretch for a bed you sleep in every night.
Why once a week?#
You spend around a third of your life in that bed, and you aren't clean the whole time. Every night the sheets collect sweat, skin oil, dead skin flakes, drool, and whatever you went to bed wearing: moisturizer, hair product, sunscreen from the afternoon. The skin flakes are food for dust mites. The oil is what leaves that gray-yellow band on the pillowcase where your face lands.
None of this shows up quickly. Sheets look fine for two or three weeks, which is why "wash them when they look dirty" doesn't work as a rule. A fixed day does. Pick a day you're already doing laundry and strip the bed that morning.
How often to wash sheets in different situations#
| Situation |
How often |
| Typical adult, showers before bed |
Weekly |
| Night sweats, hot summer, no air conditioning |
Every 3 or 4 days |
| Dust mite allergy or allergic asthma |
Weekly, in hot water if the fabric allows |
| Dog or cat sleeps on the bed |
Every 3 or 4 days, or weekly plus a washable throw on top |
| Someone had a cold or flu |
Once they're over it |
| Vomit, diarrhea, or a bedwetting accident |
Right away |
| Guest bed |
After each guest, not on a schedule |
Pillowcases can go faster than the rest of the set. If you sleep in skincare or have oily hair, swapping just the pillowcase midweek is a cheap fix.
Washing sheets for dust mite allergies#
If you or a child has a dust mite allergy, weekly washing is part of the standard advice, and so is heat. The Asthma and Allergy Foundation of America's dust mite page says to wash sheets and blankets weekly in water of at least 130°F (54°C). The NHS advice on allergic rhinitis says to wash bedding at 60°C or above. AAFA also recommends zippered allergen-barrier covers on the mattress and pillows, since mites live in those too and you can't boil a mattress.
Not every fabric survives that much heat. Cotton usually does. Linen, silk, bamboo, and most blends don't, so check the label before you crank the temperature, and lean on the covers if your favorite sheets can only take a cool wash.
After a stomach bug or bedwetting accident#
Strip the bed straight away and don't shake the sheets out, since that spreads whatever is on them. The CDC's norovirus prevention advice is to wear gloves, wash with detergent on the hottest water and longest cycle available, then machine dry on the highest heat setting. The NHS norovirus page says 60°C, washed separately from other laundry. Wash your hands afterwards, and check whether anything soaked through to the mattress protector.
What temperature should you wash sheets on?#
Use the warmest water the fabric's care label allows. Whirlpool's guide breaks it down by material:
| Fabric |
Water |
Cycle |
| Cotton |
Warm or hot |
Sheets, normal, or sanitize |
| Polyester blend |
Warm |
Sheets or normal |
| Linen |
Cold or warm |
Sheets or normal |
| Flannel |
Cold or warm |
Gentle |
| Silk, satin, bamboo |
Cold |
Gentle or delicate |
A few habits make a bigger difference than the temperature:
- Wash sheets on their own. Towels are heavier, shed lint, and dry at a different rate, so a mixed load ends with damp sheets or overdone towels.
- Skip the fabric softener. Whirlpool notes it reduces the absorbency of natural fibers, which is the last thing you want in something you sweat into.
- Check the fitted sheet before it goes in the dryer. Pillowcases and socks love to hide in the corner pockets and come out wet.
- Dry on low to medium heat and take the sheets out promptly. High heat shrinks cotton and wears out elastic corners.
If clean sheets come out smelling musty, they probably sat wet in the drum too long, or the machine itself needs attention. Our washing machine cleaning guide covers the gasket and drum.
Signs your sheets need washing now#
Don't wait for the scheduled day if you notice any of these:
- A stale or sour smell when you pull the duvet back
- Gritty bits at the foot of the bed (sand, crumbs, dried mud from a pet)
- A dull, yellowish tint on the pillowcase
- Sheets that feel slightly tacky or cool and damp from sweat
- Visible pet hair or paw prints
What else to wash when you change the sheets#
Changing the sheets doesn't clean what's under them. The duvet cover goes in with the sheets every week, but the insert runs on a much slower schedule; see how often to wash a duvet. Pillows themselves need a wash every few months, which the pillow washing guide walks through. And while the bed is bare, it's the easiest moment to vacuum the mattress.
FAQ#
Should you wash new sheets before using them?#
Yes. New sheets often feel stiff from factory finishes and can shed loose dye. One wash on the setting the label recommends softens them and gets rid of both.
How many sets of sheets do you need per bed?#
Two is the minimum, three is comfortable. With a spare set you can remake the bed immediately instead of waiting on the dryer, and one set can be in the wash after an accident without leaving you short.
Is it bad to sleep on the same sheets for a month?#
It's not a good idea. A month of sweat, oil, and skin flakes is a lot of food for dust mites and a lot of smell. For someone with a dust mite allergy or allergic asthma, it works against everything else they're doing to keep exposure down, so stick to weekly. If symptoms keep flaring at night despite clean bedding, that's worth raising with a doctor or allergist.
If weekly keeps sliding into "whenever I remember," set a recurring reminder for your laundry day in ChoreLists.com and let it nag you instead.