The most common price for a single Windows-based antivirus subscription is $39.95 per year. Bitdefender charges $49.99 for a single license, $10 above the norm, which might count against it...except that a single Norton license runs $59.99 per year, $20 above the norm.

(Credit: Bitdefender/PCMag)

If one’s not enough, you can get three Bitdefender licenses for $69.99 per year, or five Norton licenses for $84.99 per year. Presuming you use all your licenses, Norton’s per-device price is lower, but that’s not enough to win this round, which goes to Bitdefender

To supplement my antivirus testing, I closely track reports from four independent testing labs around the world. Different labs use different scoring methods, though. For example, AV-Test Institute reports numeric results, AV-Comparatives offers named certification levels, and tests by MRG-Effitas are close to simply pass/fail. I’ve devised and refined an algorithm that maps the various scores onto a 10-point scale and comes up with an aggregate score for any product with results from at least two labs. Having a high aggregate score is good, naturally, but so is having scores from many labs.