Reopening Calculator
HealthEstimate a simple community reopening readiness score from case trend direction and test positivity rate. An educational public health indicator tool.
Reopening Readiness Score (0-100)
67.5
2-Week Case Trend
-37.50%
What is a Reopening Trend?
The Reopening Calculator combines a location's recent case trend and test positivity rate into a single 0-100 composite reference score, intended to illustrate how these commonly discussed public health indicators interact. It is an educational tool, not official reopening guidance.
For related case-rate calculations, see the Incidence Rate Calculator and Event Risk Calculator.
How to use this Reopening Trend calculator
- Enter the cases this week per 100,000 people for your area of interest.
- Enter the cases from two weeks ago per 100,000 people for the same area.
- Enter the current test positivity rate.
- Read the Reopening Readiness Score and 2-Week Case Trend instantly.
- Always cross-check with official public health guidance for real decisions, since this is a simplified educational reference only.
Formula & Methodology
2-Week Case Trend (%) = ((This Week − Two Weeks Ago) ÷ Two Weeks Ago) × 100 Readiness Score = 100 − Case Penalty − Positivity Penalty − Trend Penalty + Declining Trend Bonus, capped between 0 and 100. Worked example — 50 cases this week, 80 two weeks ago, and 5% test positivity: Trend = ((50 − 80) ÷ 80) × 100 = −37.5% (declining) Readiness Score ≈ 100 − 25 (case penalty) − 15 (positivity penalty) − 0 (no rising trend penalty) + 7.5 (declining bonus) ≈ 67.5
Frequently Asked Questions
A reopening readiness score is a simplified indicator that combines a location's recent case trend and test positivity rate into a single 0-100 reference number, intended as an educational way to visualize how these public health indicators move together, not an official reopening decision tool.
The calculator starts at 100 and subtracts penalties based on the current case level, the test positivity rate, and whether the case trend is rising, with a small bonus applied if cases are declining — giving a single composite reference figure.
Test positivity rate is the percentage of administered tests that come back positive; a lower positivity rate generally suggests more comprehensive testing relative to actual case levels, while a high rate can suggest testing is missing many cases.
A moderate case level that's rapidly rising suggests a different trajectory than the same case level that's declining, so tracking the direction of change gives important context beyond a single snapshot figure.
No — official reopening decisions are made by public health authorities using far more comprehensive data, context, and expertise than this simplified educational calculator provides. This tool is for general reference and understanding indicator trends, not for making real reopening decisions.
A low score reflects higher case levels, higher test positivity, and/or a rising trend based on the specific inputs entered — it's a relative indicator for the entered figures, not an absolute safety threshold.
Public health indicators like case counts and test positivity are typically updated regularly (often weekly) by local health authorities, so re-running this calculator with updated figures gives a more current, though still simplified, reference picture.
Yes — enter the case and positivity figures for whatever location you're interested in tracking; the calculator itself is location-agnostic and depends entirely on the data you provide.
The [Incidence Rate Calculator](/incidence-rate-calculator/) computes a single rate from case and population data, while this calculator combines a case trend and test positivity into one composite reference score — both use case-related data but present it differently.
This calculator is intended for general education about how public health indicators interact, not as a substitute for official guidance or personal risk assessment, which should rely on current, authoritative public health information.
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