Key Points
There are six different rating systems on manuka honey labels. Only two of them tell you something meaningful about antibacterial potency. The others measure purity, pollen count, or nothing independently verified at all.
UMF is the most comprehensive and trustworthy system. It tests four compounds simultaneously and is regulated by an independent New Zealand nonprofit. It is the one rating worth prioritizing.
MGO is a reliable secondary measure but tests only one compound. A jar with only MGO on the label has not been independently verified to the same standard as a UMF-certified jar.
KFactor, BioActive, and Active labels do not measure antibacterial potency. A KFactor number and a UMF number cannot be compared directly. They measure entirely different things.
For everyday wellness, UMF 10 from a licensed producer is the best value starting point. For skin and targeted use, UMF 15 or above. The grade should match the job.
The manuka honey buying guide most people need does not exist yet. There are plenty of articles explaining what UMF means. There are brand pages telling you their system is the best one. What is missing is a clear, editorially independent guide that explains every rating system on the market, which ones actually measure what they claim, which ones are misleading, and how to use that information to buy a jar you can trust.
This is that guide. We have no label to sell and no grading system to defend.
Here is exactly what each number on a manuka honey jar means.
Why There Are So Many Different Manuka Honey Ratings
The short answer is that the manuka honey market grew faster than any single standard could control it. When scientists first identified the unique antibacterial properties of manuka honey in the 1980s, the measure used was called Non-Peroxide Activity (NPA). From there, the industry developed multiple competing systems, some rigorous and independently verified, others created by individual brands for marketing purposes.
Today a consumer standing in front of a shelf of manuka honey jars might see UMF, MGO, MGS, NPA, KFactor, BioActive, or Active on the label, sometimes in combination, sometimes alone. These numbers look similar but they measure very different things. Some measure potency. Some measure purity. Some measure pollen count. And some measure nothing independently verified at all.
Understanding the difference is the most important thing you can do before spending $40 to $200 on a jar. Our full guide to why manuka honey is so expensive explains the pricing picture. This guide explains what the labels actually mean.
The Two Categories of Manuka Honey Numbers
Before diving into each system, it helps to understand that all manuka honey numbers fall into one of two categories.
The first category is full grading systems. These measure multiple compounds in the honey and typically involve independent third-party testing and certification. UMF and MGS fall into this category. They test for more than one
