10 Scariest Horror Movies According To Viewer Heart Rate

When you talk about the best or worst or in this case, scariest horror movies out there, you are usually relying on personal opinion, even if you’re citing somewhere like Rotten Tomatoes, an amalgam of personal opinions. But there’s a project that tries to measure the scariest movies in existence using science. You can choose to believe it or not, but they have data to present.

This is the Science of Scare project, an ongoing experiment via MoneySuperMarket that uses viewer heartbeat changes to map out which horror movies are the scariest in terms of how much they result in a physiological change in the audience. Perfect scientific methodology? Unlikely, but it’s fun to see all the same, and see if you agree or disagree with the top 10.

Here’s how this is calculated, according to those running the project:

“The Scare Score system, which combines both heart rate (measured in beats per minute BPM), and heart rate variance (measured in milliseconds, or m/s), returns for 2025. With heart rate (BPM), the higher the number, the faster the movie got our audiences’ blood pumping, an indicator of excitement and fear as part of your fight or flight instinct.

“On the other hand, heart rate variance (HRV), measures the time in between each beat of your heart. The lower the heart rate variance the more stressed our audience members became, a good indicator of slow burn fear and dread.

“After collecting the average heart rate increase and HRV decrease, we then combine both scores to create a Science of Scare Score out of 100. For comparison, Shrek holds a ‘Scare Score’ of 3 out of 100.”

I love how they use Shrek as a control group. Anyway, here is the top 10 list of scariest horror movies:

Source: https://www.forbes.com/sites/paultassi/2025/10/20/10-scariest-horror-movies-according-to-viewer-heart-rate/