This calculator allows you to assess whether anti-terrorism efforts are worth their cost or not.

The values that you see already in each input box are based on an analysis 9/11 style attacks and the efforts America has made to prevent them since 2011. To see the basis for these assumptions, click here.

Change the values as you see fit for this scenario, or analyze a completely different scenario.

Once you've filled in the assumptions and hit "Calculate," a table will populate with the total cost of a terrorist attack, the total cost of deterrence or lack thereof, the expected number of attacks, and the varying expected lives lost over the assumed time period.


Total Impact of Terrorist Attack: $ billion (GDP, property damage)
Lives lost in a terrorist attack:
Monetary Value of a Life: $ million
Cost to Prevent: $ billion per year (The cost of Overseas Contingency Operations in 2016. If you'd like to add in law enforcement and intelligence costs, add $69 billion for a total of $119.9 billion)
Annual Chance of Attack without Counter-Terrorism Efforts: %
Annual Chance of Attack with Counter-Terrorism Efforts: %
Alternative Investment Return (infrastructure, education, research): %
Defense-Specific Inflation Rate:
# of iterations you'd like to run: (If you are unfamiliar with Monte Carlo simulations, leave this at 10000)
How long of a time period do you want to analyze?: years (The number of years you want your scenario to last)