doomath Calculator
Virus Spread Calculator
Explore outbreak growth, reproduction number, intervention effects and transmission probability with a transparent mathematical model.
🦠 OUTBREAK MATHEMATICS
Spread grows in this simplified model
This is an educational growth model, not a forecast or medical decision tool. See how reproduction, timing and intervention reshape an outbreak curve.
Effective R1.75
Model inputsEvery assumption updates the presentation instantly.
What the model saysTransparent mathematical outputs.
Outbreak curveGeneration-based exponential model capped at population size.
I(t) = I₀ × R^(t/G)infectedtime → 60 days
🎯 Transmission probabilityA separate probability model for repeated exposure.
100.0%
With 8.0% probability per exposure and 4 exposure opportunities per day:P(at least one) = 1 − (1 − p)ⁿ
📐 The math behind itSimple enough to inspect, useful enough to teach.
- R₀ represents average secondary infections under the chosen baseline assumptions.
- Intervention produces R = R₀ × (1 − reduction).
- Each generation multiplies the modeled count by R: I(t) = I₀R^(t/G).
- Repeated exposure compounds probability using 1 − (1 − p)ⁿ.
Calculator guide
How to use the Virus Spread Calculator
Explore simplified outbreak growth, reproduction number, intervention effects and repeated-exposure transmission probability.
01Set inputsChoose values, units and assumptions.
02Apply the modelI(t) = I₀ × R^(t/G); P(at least one) = 1 − (1 − p)^n
03Read the resultCheck the output against the assumptions before using it.
What this calculator does
This educational model combines a generation-based outbreak growth model with a separate repeated-exposure probability model.
Formula & method
I(t) = I₀ × R^(t/G); P(at least one) = 1 − (1 − p)^n
Assumptions & notes
- Educational model, not a medical forecast.
- Real outbreaks require susceptible depletion, immunity, behavior, reporting and many other factors.
- The coronavirus-style preset is illustrative, not a historical estimate.