A dripping compression faucet is a 15-minute fix, and the part that fixes it costs under a dollar: the faucet washer. This guide covers standard faucet washer sizes, flat vs beveled washers, the best rubber material for hot and cold taps, and the step-by-step replacement.
Standard faucet washer sizes
US compression faucets use trade sizes that map to real dimensions like this:
| Trade size | Approx. OD | Common use |
|---|---|---|
| 00 | 1/2" | Small older fixtures |
| 0 | 9/16" | Bathroom faucets |
| 1/4 | 5/8" | Bathroom faucets |
| 3/8 | 11/16" | Bathroom/kitchen |
| 1/2 | 3/4" | Kitchen faucets, hose bibbs |
| 3/4 | 13/16"–7/8" | Outdoor spigots, laundry taps |
The most reliable method: take the old washer out and measure it — OD across the face, ID through the screw hole (usually accepts a #8–#10 brass screw), and thickness (typically 1/8"–3/16"). Our how-to-measure guide walks through it, and the size chart lists every OD/ID/thickness we stock.
Flat vs beveled faucet washers
Flat washers seal against a flat valve seat; beveled (cone) washers seal against a rounded or worn seat. If a flat washer keeps dripping after replacement, the seat is likely worn — a beveled washer is more forgiving, or dress the seat with a seat-grinding tool.
Best material for faucet washers
EPDM is the top choice for water service: rated well past domestic hot-water temperatures, unaffected by chlorine and chloramine, and it stays flexible for years. Neoprene is a solid all-rounder for cold lines. For very hot lines (commercial dishwashers, near-boiler fixtures), silicone handles the heat best but is softer, so use it on smooth seats. Avoid nitrile — it's built for oil, not chlorinated water. More detail in our plumbing washer guide.
How to replace a faucet washer (compression faucet)
- Shut off the water under the sink and open the faucet to drain it.
- Pry off the handle cap, remove the handle screw and handle.
- Unscrew the packing nut and lift out the valve stem.
- Remove the brass screw at the bottom of the stem holding the old washer.
- Match the new washer's size and profile (flat or beveled), install it, and snug the screw.
- Reassemble, turn the water on slowly, and check for drips.
FAQ
Why does my faucet still drip after replacing the washer?
Three usual causes: wrong washer size (too small won't cover the seat), a worn valve seat that needs dressing or a beveled washer, or a cracked stem. Size is the most common miss — measure the old washer rather than guessing.
Are faucet washers universal?
No. Sizes range from 1/2" to 7/8" OD across fixtures. That's why we sell exact sizes individually instead of assortment kits — you buy the dimension your faucet actually needs.
What size washer does an outdoor spigot use?
Most hose bibbs and outdoor spigots take a 3/4 trade size washer, around 13/16"–7/8" OD. See our garden hose & tap washer guide for the hose-end washers too.
How long do rubber faucet washers last?
EPDM washers typically last 5–10 years in domestic service. Hard water and very hot lines shorten that; frequent partial closing (which grinds the washer against the seat) shortens it further.