Probiotic CFU Comparison
Compare probiotics by what they cost per billion CFU, not just the big number on the front.
This tool was built by Serge (MSc) using established science and government sources. My academic background covers plant biology, environmental biology, and biogeochemistry. My tools are for educational purposes and give practical guidance, not professional advice.
Probiotic labels lead with a big CFU number, but the real question for value is what each billion CFU costs you. This tool works that out. Enter the price, the CFU per serving in billions, and the servings per container, then run it again for another product to compare. Read the important note below first, because more CFU is not the same as better.
How this works
The tool finds the cost of one serving, then divides by the CFU in that serving:
Cost per serving = price ÷ servings
Cost per billion CFU = cost per serving ÷ CFU in billions
For example, a container priced at 30 with 30 servings costs 1 per serving. If each serving has 50 billion CFU, that is 1 ÷ 50, or about 0.02 per billion CFU. Running two products this way shows which gives more live cultures for the money.
Understanding your result
A lower cost per billion CFU means more live cultures for your money, which is useful for comparing similar products. It is a value figure, not a health verdict. Use it to spot when a product with a smaller headline number is actually the better deal per CFU, or when a very high CFU count comes at a steep price.
Important note
- Higher CFU does not mean better. Health authorities are clear that a higher CFU count alone does not mean greater benefit. The specific strains matter as much as the number.
- Match like with like. Compare products with similar strains and a CFU count guaranteed through the expiry date, not just at the time of manufacture.
- Storage affects the real count. Some probiotics lose viability if not stored as directed, so the label number is a starting point.
- This compares cost and CFU only, not quality, strains, or how well a product suits a particular purpose.
Scientific basis
The meaning of CFU and the caveat that more is not automatically better come from the NIH Office of Dietary Supplements:
- Probiotics fact sheet for consumers, NIH Office of Dietary Supplements
- Probiotics fact sheet for health professionals, NIH Office of Dietary Supplements
This calculator is for general education only and is not medical or professional advice. Always check product labels and speak with a qualified professional before making decisions about supplements.