The WHO recipes were designed for local production in health facilities. Hydrogen peroxide inactivates spores in the ingredients and glycerol protects the skin. Final alcohol content must be at least 60–80% to be effective; soap and water are preferred when hands are visibly dirty.
How to use the Hand Sanitizer Calculator
- Formulation
- Batch volume
- Strength of your alcohol
Results update as you type, and every field accepts the units shown in its menu.
How it works
Choose the formulation, batch size and the strength of your alcohol.
Tips
- Use counts and person-time from the same population and period.
- Report confidence intervals with rates and ratios.
- Check whether figures are crude or age-adjusted before comparing.
- Larger samples give more stable estimates.
Common mistakes to avoid
- Confusing incidence (new cases) with prevalence (all cases).
- Comparing rates per 1,000 with rates per 100,000.
- Reading a relative risk without the baseline risk.
Inputs explained
| Field | What to enter |
|---|---|
| Formulation | Choose one: Ethanol (WHO formulation 1, 80%), Isopropyl alcohol (WHO formulation 2, 75%) |
| Batch volume | Units: mL, L, fl oz |
| Strength of your alcohol | In % |
What each result means
- 3% hydrogen peroxide = [Batch volume]×0.0417
- 98% glycerol = [Batch volume]×0.0145
- Sterile or boiled cooled water = max([Batch volume] – [Alcohol] – [3% hydrogen peroxide] – [98% glycerol], 0)
- Final alcohol concentration = min([Alcohol]×[Strength of your alcohol]÷100÷[Batch volume]×100, 100)
Example values
How the main result changes when Batch volume changes and everything else stays at the example values above:
| Batch volume (mL) | Alcohol (mL) |
|---|---|
| 500 | 417 |
| 750 | 625 |
| 1,000 | 833 |
| 1,250 | 1,042 |
| 1,500 | 1,250 |
| 2,000 | 1,667 |
Health note: this calculator is for education and screening only and is not a diagnosis or treatment advice. Discuss your results with a qualified clinician.
Formula
WHO formulation 1 (per 10 L): 96% ethanol 8,333 mL · 3% hydrogen peroxide 417 mL · 98% glycerol 145 mL · water to 10 L → 80% v/v ethanol
WHO formulation 2: 99.8% isopropyl alcohol 7,515 mL, same other ingredients → 75% v/v
Worked example
Inputs — Formulation: Ethanol (WHO formulation 1, 80%); Batch volume: 1,000 mL; Strength of your alcohol: 96 %.
Results — Alcohol = 833 mL; 3% hydrogen peroxide = 41.7 mL; 98% glycerol = 14.5 mL; Sterile or boiled cooled water = 110 mL; Final alcohol concentration = 80 %.
Key terms
- v/v
- Volume per volume.
Frequently asked questions
What alcohol concentration is effective?
At least 60% ethanol or 70% isopropanol; WHO uses 80% and 75%.
Why add hydrogen peroxide?
It kills bacterial spores in the ingredients and containers.
Can I use rubbing alcohol at 70%?
It is too weak to reach 75% after adding the other ingredients.