Coronavirus Mask Calculator
Calculate how many face masks you need for COVID-19 protection. Estimate costs, boxes, and supply duration for households, offices, or events.
| Week | Masks Used | Cumulative | Remaining | Status |
|---|
About
Underestimating PPE supply leads to either dangerous shortages or wasteful overspending. A single surgical mask should be replaced every 4 - 8 hours of continuous use according to WHO guidelines. N95 respirators degrade faster under humid conditions and should not be reused beyond manufacturer specifications. This calculator applies the consumption formula T = N × R × D × (1 + S) where S is a safety buffer to account for damaged, contaminated, or lost units. It rounds up to the nearest commercial box size because masks are not sold individually at wholesale.
The tool differentiates between mask types because replacement intervals vary. Cloth masks require washing after each use and degrade after approximately 30 wash cycles. N95 and KN95 respirators cost 3 - 5× more than surgical masks but offer superior filtration at ≥95% of airborne particles ≥0.3μm. This approximation assumes consistent daily usage patterns and does not account for high-exposure medical environments where consumption can double.
Formulas
The total mask requirement is computed as:
Where T = total masks needed, N = number of people, R = masks per person per day (replacement rate), D = duration in days, and S = safety stock percentage.
Box rounding uses the ceiling function to ensure you never under-order:
Where B = boxes to purchase, Q = masks per box, and ⌈ ⌉ denotes the ceiling function.
Total estimated cost is:
Where C = total cost and P = price per mask. Note this uses the rounded box total (actual masks purchased), not the theoretical minimum, so the real cost reflects what you actually buy.
Reference Data
| Mask Type | Filtration Efficiency | Max Wear Time | Reusable | Typical Box Size | Approx. Cost/Unit | Best For |
|---|---|---|---|---|---|---|
| Surgical (Level 1) | ≥95% bacterial | 4 - 8 hrs | No | 50 | $0.10 - 0.30 | General public, low-risk |
| Surgical (Level 3) | ≥98% bacterial | 4 - 8 hrs | No | 50 | $0.20 - 0.50 | Healthcare, high-risk |
| N95 Respirator | ≥95% particles ≥0.3μm | 8 hrs | No (some decontaminable) | 20 | $1.00 - 3.00 | Healthcare, high-exposure |
| KN95 | ≥95% particles ≥0.3μm | 8 hrs | No | 20 - 50 | $0.50 - 2.00 | General public, moderate risk |
| KF94 | ≥94% particles ≥0.4μm | 8 hrs | No | 25 - 50 | $0.80 - 2.50 | Daily use, good fit |
| FFP2 (EN 149) | ≥94% particles | 8 hrs | NR (non-reusable) / R | 20 | $1.00 - 3.50 | EU standard, healthcare |
| FFP3 (EN 149) | ≥99% particles | 8 hrs | NR / R | 10 - 20 | $3.00 - 6.00 | Aerosol-generating procedures |
| Cloth (2-layer cotton) | 50 - 70% droplets | 4 - 8 hrs | Yes (~30 washes) | 1 - 5 | $3.00 - 15.00 | Low-risk, reusable |
| Cloth (3-layer w/ filter) | 70 - 80% droplets | 4 - 8 hrs | Yes (~30 washes) | 1 - 5 | $5.00 - 20.00 | Daily commute |
| P100 Respirator | ≥99.97% particles | Per manufacturer | Yes (cartridge replacement) | 1 | $25.00 - 50.00 | Industrial, extreme exposure |
| Face Shield (supplement) | Splash protection only | Reusable indefinitely | Yes | 1 | $5.00 - 15.00 | Supplemental to mask |
| Elastomeric Half-Face | Depends on cartridge (P95 - P100) | Cartridge: 40 hrs | Yes | 1 | $20.00 - 35.00 | Long-term reusable PPE |
| PAPR (Powered Air) | ≥99.97% | 8 - 12 hrs battery | Yes | 1 | $500 - 2000 | Hospitals, long shifts |