How long should I rub my hands together when washing them?

September 22, 2025 •

4 min read

According to the Centers for Disease Control and Prevention (CDC), proper handwashing is one of the best ways to prevent the spread of germs. But how long should I rub my hands together when washing them to achieve maximum effectiveness?

Quick Summary

Rubbing your hands together for at least 20 seconds is the recommended scrubbing time for effective handwashing, which physically dislodges germs from your skin's surface. This friction-based action, combined with soap, is crucial for breaking down the fatty membranes of viruses and bacteria, ensuring a thorough clean.

Key Points

20-Second Scrub: The CDC recommends rubbing your hands with soap for at least 20 seconds to effectively remove germs.
Friction is Key: The mechanical action of rubbing helps to physically lift and dismantle germs from the skin's surface.
Micelles Trap Germs: Soap creates micelle molecules that trap and lift dirt, oils, and pathogens, which are then rinsed away.
Comprehensive Coverage: Ensure you scrub all areas, including palms, backs of hands, between fingers, and under nails.
Proper Drying is Crucial: Germs spread more easily on wet hands, so drying them completely is a critical final step.
Timing Techniques: Singing "Happy Birthday" twice or counting slowly to 20 are simple ways to ensure you meet the recommended time.
Hand Sanitizer Limitations: Hand sanitizer is a good backup but is less effective than soap and water, especially on visibly dirty hands.

Why the 20-Second Rule Matters

The 20-second handwashing rule isn't an arbitrary recommendation; it's a scientifically-backed guideline designed to give soap enough time to do its job. Germs are microscopic and cling to the natural oils on our skin. When you use soap and rub your hands together, the soap creates a lather with tiny molecules called micelles. These micelles trap the germs and dirt, lifting them off your skin. The vigorous rubbing action, for the full 20 seconds, ensures that the lather reaches all areas—palms, backs of hands, between fingers, and under nails—to effectively remove pathogens.

The Science Behind the Scrub

To understand why friction and time are so important, consider the structure of many viruses and bacteria. Many, including enveloped viruses like the flu and COVID-19, have a lipid envelope or fatty outer layer. Soap is a surfactant, meaning it breaks down these fatty layers. A brief, cursory wash doesn't allow enough time for the soap to disrupt these layers effectively across the entire surface of your hands. The 20-second scrub, combined with the lather, provides the necessary mechanical action to physically dismantle and remove these microscopic threats.

The Step-by-Step Guide to Proper Handwashing

For a truly effective hand wash, follow these steps recommended by public health authorities like the CDC:

Wet Your Hands: Use clean, running water (warm or cold). Turn off the tap to save water while you lather.
Apply Soap: Lather a generous amount of soap onto your wet hands.
Rub and Scrub: Rub your hands together vigorously for at least 20 seconds. Ensure you cover all surfaces, including:
- Palms
- Backs of your hands
- Between your fingers
- The base of your thumbs
- Under your fingernails
- Your wrists
Rinse Thoroughly: Rinse your hands well under clean, running water until all soap is removed.
Dry Properly: Dry your hands completely with a clean towel or an air dryer. Germs can spread more easily on wet hands, so this step is critical.

Visual Aids for Timing Your Wash

Many people struggle to gauge what 20 seconds feels like. Fortunately, there are several simple tricks to help you get the timing right:

The Happy Birthday Song: Singing the "Happy Birthday" song from beginning to end twice takes approximately 20 seconds. This is a common and effective method, especially for children.
Other Songs: If you prefer, other song snippets also work, such as the chorus of “Let It Go” or “Twinkle, Twinkle, Little Star.”
Count to 20: Simply counting to 20 slowly is another reliable method to ensure you hit the target time.

Comparison: Standard Wash vs. 20-Second Wash


Feature	Quick, Less-Than-20-Second Wash	Recommended 20-Second Wash
Germ Removal	Incomplete and less effective. Some pathogens remain on hands, risking transmission.	Thorough and highly effective. Removes a significant portion of harmful germs.
Lathering	Inadequate, with minimal micelle formation to trap germs.	Full, robust lather that effectively traps and lifts dirt and pathogens.
Coverage	Misses critical areas like the backs of hands, between fingers, and under nails.	Ensures all surfaces of the hands are adequately scrubbed and cleaned.
Disease Prevention	High risk of cross-contamination and spreading illness.	Drastically reduces the risk of contracting and spreading infectious diseases.
Public Health Impact	Contributes to the spread of community-wide infections.	Contributes to a healthier community by lowering overall transmission rates.

The Importance of Handwashing Frequency

Beyond the duration of the scrub, it's vital to wash your hands at the right times. Frequent handwashing throughout the day is a cornerstone of good hygiene. Key moments include:

Before, during, and after preparing food.
Before eating.
Before and after caring for someone who is sick.
Before and after treating a cut or wound.
After using the toilet.
After changing diapers or cleaning up a child who has used the toilet.
After blowing your nose, coughing, or sneezing.
After touching garbage.
After handling pets, pet food, or pet waste.

Can't I just use hand sanitizer?

While hand sanitizer is a good alternative when soap and water are not available, it is not a perfect substitute. Hand sanitizers with at least 60% alcohol can significantly reduce the number of germs but do not remove all types of germs and may not be as effective when hands are visibly dirty or greasy. The mechanical action of soap and water is superior for removing dirt and grime.

Conclusion

The small time investment of 20 seconds for hand scrubbing offers a huge return in the form of better personal and public health. By understanding the science behind the scrub and incorporating this simple habit into your routine, you can significantly reduce your risk of illness. It's a proactive measure that empowers you to take control of your health and protect those around you. For more resources on preventing the spread of germs, you can consult the Centers for Disease Control and Prevention website. Making this commitment to thorough handwashing is one of the most effective and accessible ways to stay healthy.

Frequently Asked Questions

The 20-second duration allows enough time for the soap to form a full lather and for the physical friction of rubbing to effectively dislodge and remove germs from all surfaces of your hands, a process validated by scientific studies.

A simple and effective way to time your wash is to sing the "Happy Birthday" song twice from beginning to end. Alternatively, you can count to 20 slowly or use a physical timer.

Yes, clean running water of any temperature (warm or cold) is effective for handwashing, as the combination of soap and friction is what removes the germs. Some research even suggests warm water may be more irritating to the skin than cold water.

Drying your hands thoroughly is very important. Germs spread more easily on wet hands than on dry hands. Using a clean paper towel, a clean cloth towel, or an air dryer is the best practice.

Regular soap is just as effective as antibacterial soap for removing germs and dirt. The mechanical action of scrubbing with any soap is the primary germ-removing mechanism. Overuse of antibacterial products may also contribute to antibiotic resistance.

No, hand sanitizer is not a complete replacement. While it can reduce germs, it is less effective on visibly dirty or greasy hands and does not remove all types of pathogens. Use soap and water when available for the most thorough clean.

While vigorous rubbing is part of the process, it does not allow you to shorten the 20-second timeframe. The time is necessary for the soap and friction to work on all areas of your hands effectively, ensuring comprehensive coverage and removal of germs.