Use this calculator to assess the Medial Incapacitation Performance (MIP) of any handgun cartridge. MIP is a metric built entirely on the real-world data described on the “Handgun Performance” page. For each caliber in the empirical data, MIP was the actual incidence of incapacitation that fell midway between immediate incapacitation with the first head or torso hit and eventual incapacitation with any number of hits. The “Stopping Power %” returned by the calculator is the projected MIP using the formula that mirrored the empirical data. MIP roughly corresponds to a 2-shot-stopping-power (based on some standard probability assumptions), but it’s built solely on real-world data instead. So far, known values for this measure of Stopping Power range from 44% for 25 ACP to 87% for 500 S&W.
Medial Incapacitation Performance (MIP)
Stopping Power Calculator
So what’s a “good” MIP Stopping Power? I personally like percentages in the upper 60s (or higher); they mean there’s about a 2/3s chance of incapacitating with just a couple of well-placed shots. Of course, there are a number of trade-offs in your “best-handgun-for-me” decision: your accuracy with a particular caliber or gun, ease of carry, stopping power, … . MIP is just one data point to help you in that calculus.
We can also assess the number of shots needed to reach a 90% probability of incapacitation … given the Stopping Power value generated by the calculator above, and using some standard probability calculations and assumptions. Use this information with caution; the Stopping Power calculation is solidly backed by real-world data, while the chart below relies on some necessary assumptions. But the chart does provide a related result that is sometimes more intuitively understood (if less reliable). A few common calibers are marked on the chart.
