Mask Supply Calculator — How Many Masks Do You Need?
Work out how many face masks a household, team, or organisation needs over a given period, compare the filtration effectiveness of N95, KN95, surgical, and cloth masks, and estimate the total cost.
people
days
Mask type
$
Surgical / medical mask · up to 1 day(s) reuse per mask
- 1
Masks per person per day
1 ÷ 1 = 1Each Surgical / medical mask can be reused for up to 1 day(s). - 2
Total masks (before rounding)
4 × 30 × 1 = 120 - 3
Masks needed (rounded up)
⌈120⌉ = 120Always round up to ensure full coverage for every person.
How does this calculator work?
Divide your protection period (days) by the safe reuse limit of the chosen mask, then multiply by the number of people to get the total mask count. N95 respirators filter ~95 % of particles but require fit-testing; surgical masks filter ~75 %; cloth masks vary from 20–50 %. Fit matters as much as rated efficiency.
Formula
How this is calculated
The total number of masks required depends on how many people are being protected, how long the period lasts, and how many days each mask can safely be reused. N95 and KN95 respirators can be reused for up to 5 donning cycles under normal, non-contaminated conditions according to CDC emergency guidance (not standard use); surgical masks are intended for single sessions; cloth masks are washable and can be reused indefinitely. The calculator divides the duration by the reuse limit to get the masks-per-person-per-day rate, multiplies by the number of people and days, and rounds up to a whole number.
Filtration efficiency is the percentage of airborne particles (by size ≥ 0.3 µm) that the mask material captures under test conditions. NIOSH-approved N95 respirators must filter at least 95 % of particles; KN95 masks (Chinese standard GB2626) are rated at 94 %; standard surgical masks block approximately 60–80 % of larger droplets but are much less effective against fine aerosols; cloth masks vary enormously with layer count and fabric. These figures are guide estimates from published literature as of 2025 — actual performance depends on fit, fabric, and condition.
Proper fit is as important as filtration efficiency. An N95 that does not form a tight seal offers no better protection than a surgical mask. The protection shown here assumes ideal wearing conditions.
Frequently asked questions
An N95 is a tight-fitting respirator that filters at least 95 % of airborne particles, including fine aerosols, when properly fitted. A surgical mask is a loose-fitting barrier that mainly blocks large respiratory droplets; it does not seal around the face and typically filters only 60–80 % of particles. N95s provide significantly higher protection against airborne transmission.
Under normal single-user conditions and if not visibly soiled or damaged, an N95 can be re-donned up to 5 times or for a total of 8 hours of use, per US CDC emergency guidance. Let masks dry between uses and avoid touching the inside. Discard immediately if wet, visibly dirty, or if breathing becomes difficult.
A well-made cloth mask can be washed and reused many times — the limiting factor is fabric degradation, not a fixed number of uses. Wash after each day of use, inspect for stretched ear loops or thinning fabric, and replace when the material becomes thin or the fit becomes loose. Filtration efficiency for cloth masks ranges widely (10–50 %) depending on material, layers, and weave density.
Also known as
TG we-Calculate Editorial Team. (2026). Mask Supply Calculator — How Many Masks Do You Need? [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/coronavirus-mask-calculator
TG we-Calculate Editorial Team. "Mask Supply Calculator — How Many Masks Do You Need?." TG we-Calculate. 2026. https://we-calculate.com/calculator/coronavirus-mask-calculator.
TG we-Calculate Editorial Team, "Mask Supply Calculator — How Many Masks Do You Need?," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/coronavirus-mask-calculator
@misc{wecalculate_coronavirus_mask_calculator, title = {Mask Supply Calculator — How Many Masks Do You Need?}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/coronavirus-mask-calculator}}, year = {2026}, note = {TG we-Calculate} }
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