How to use the disease prevalence calculator
Find the percent and per-1000 prevalence of infection in a sampled population. Enter number infected, number sampled in the fields above; the prevalence, cases per 1000 sampled are computed instantly and plotted on the chart so you can see how the answer changes.
Common searches this calculator answers include “prevalence calculation”, “infection rate in sample”, “cases per 1000 people”, “calculate disease prevalence”, “find prevalence”.
Formula
Variables
- inf — Number infected (individuals)
- tot — Number sampled (individuals)
Worked example
With number infected = 45 individuals, number sampled = 300 individuals, the calculator gives prevalence ≈ 15 %; cases per 1000 sampled ≈ 150 per 1000.
Frequently asked questions
What is the disease prevalence calculator used for?
Find the percent and per-1000 prevalence of infection in a sampled population. It helps with questions such as “prevalence calculation”, “infection rate in sample”, “cases per 1000 people”.
What is the formula for the disease prevalence calculation?
Prevalence (%) = inf / tot × 100. Cases per 1000 sampled (per 1000) = inf / tot × 1000. Here inf is number infected (individuals), tot is number sampled (individuals).
What inputs do I need for the disease prevalence calculator?
You need number infected in individuals, number sampled in individuals. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use the disease prevalence calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the disease prevalence result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.