An interactive tool to see your impact on COVID-19 curve flattening
Element AI Element AI
March 19 5 min

An interactive tool to see your impact on COVID-19 curve flattening

The quick growth in cases of COVID-19 led a team of current and past Elementals to brainstorm on how to help people understand the impact of applying social distancing measures. In a weekend hackathon they built a tool to help you understand how your actions can prevent the spread of coronavirus in your community.

Social distancing is being promoted as the main tactic to control the spread of the Coronavirus. You’ve probably seen scary curves of the number of infected individuals, or graphs about the importance of flattening the curve to limit the load upon healthcare systems.

Flattening the Coronavirus spread curve.

However, it can be hard to reason about the likely progression of the disease because there are lots of unfamiliar concepts (like exponential growth) and potentially important variables (like how quickly people get diagnosed and how long the disease remains transmissible).

This makes it difficult for non-expert individuals to reason about how they should change their behaviour, and what kind of difference that is likely to make to the things we care about: deaths and social disruption. I guess we should all work remotely? Is it ok to go to hockey games? Should I go to brunch?

A tool to see your individual impact on global numbers

The Corona Calculator is a tool to help understand how the disease might progress depending on the number of social contacts an infected person has. It aims to surface how limiting our social interactions can affect the spread of Coronavirus and the load upon healthcare systems where you live.

Corona calculator UI

Find the app here:

How to use the tool

What’s going on in my country?

When you get on the app, start by selecting your location. Every hour we check the numbers from John Hopkins and use these to provide you with the current number of confirmed cases in your region, and the historical trajectories:

Covid-19 spread in Canada

One of the tricky things about containing the Coronavirus is that we know that we don’t really know how many cases there are at any one time. We use numbers from a recent Science paper to estimate that the true number of cases at any one time is about 7x the number of confirmed cases. However, this is highly dependent upon testing strategy: there’s massive variation in the pervasiveness of testing worldwide.

How can I affect the spread?

The major thing you can control as an individual is how much you choose to self-isolate. This is reflected in the app by the number of people that an infected person interacts with each day. It’s a very important number, because it determines how quickly the disease spreads: what’s known as the basic reproduction rate in epidemiology.

How we affect the spread of Covid-19

You can zoom in and out on the graphs to see more closely what is happening at a given time

Understanding the impact on your healthcare system

Some percentage (calculated to be about 15%, based on this paper) of people require hospitalization after catching coronavirus, with symptoms ranging from respiratory distress to organ failure. This means that a lot of people are going to need hospital care, and it will put an unbelievable stress upon our healthcare systems.

Impact of Covid-19 on our healthcare system.

Again, the degree of social distancing is a key determinant of load upon hospitals. By limiting the number of people who have the disease at any one time - through social distancing - we can reduce the strain on our hospitals.

How severe will the impact of coronavirus be?

Severity of Covid-19 impact.

Finally, we estimate the hospitalization and deaths in your country by age group. Older people are much more vulnerable than younger people. Our numbers come from a very influential paper recently published by Imperial College London.

Many people will probably die from this outbreak. We can limit this number by limiting the load on the healthcare system and slowing the spread.

Everybody has a choice

If you play with the tool, you’ll see there’s a huge difference between 5 social contacts a day and 20 a day. At < 5 contacts a day, the disease doesn’t spread. In many countries, at < 10 a day, demand remains within hospitals capacity to cope.

In Canada, we estimate that the difference between 5 and 20 social contacts a day could be around 279,600 deaths.

Governments have issued guidelines, but ultimately in many countries individuals still have a choice: they set the degree of social distancing they engage in. We all have to decide for ourselves: should I go to brunch?

We think the answer is no.


This tool was built by technologists, not epidemiologists, and was made this in a rush (everything about coronavirus happens fast…). There’s many ways it could prove to be wrong, both on the numbers side and model side. See our documentation for details of our working and check out our open source codebase to contribute!

This is a personal project involving some Element AI employees, not an official project of Element AI.