Analyze converted counts from liquid plating and solids. Enter density, extract volume, dilution, and mass. Download results, inspect trends, and validate calculations with examples.
Wet-Basis CFU/g = (CFU/mL × Extract Volume × Dilution Factor) ÷ Sample Mass
Recovery-Adjusted CFU/g = Wet-Basis CFU/g ÷ (Recovery % ÷ 100)
Conversion Factor = (Extract Volume × Dilution Factor) ÷ Sample Mass
This approach converts a concentration measured in liquid suspension into a mass-based concentration. It assumes the measured liquid count represents the prepared extract or homogenate for the weighed sample.
| Sample | CFU/mL | Extract Volume (mL) | Dilution Factor | Sample Mass (g) | Recovery % | Wet-Basis CFU/g | Adjusted CFU/g |
|---|---|---|---|---|---|---|---|
| Sample A | 25000.0000 | 90.0000 | 10.0000 | 25.0000 | 100.0000 | 900000.0000 | 900000.0000 |
| Sample B | 180000.0000 | 225.0000 | 1.0000 | 50.0000 | 100.0000 | 810000.0000 | 810000.0000 |
| Sample C | 3200.0000 | 100.0000 | 100.0000 | 20.0000 | 80.0000 | 1.6000e+6 | 2.0000e+6 |
| Sample D | 95000.0000 | 250.0000 | 10.0000 | 25.0000 | 70.0000 | 9.5000e+6 | 1.3571e+7 |
Microbiology workflows often start with a liquid extract prepared from a solid sample. After plating, counting, or instrument-based estimation, the concentration may be reported as CFU/mL. Laboratories may still need a final value in CFU/g because many specifications, trend sheets, and product comparisons use mass-based reporting.
This calculator helps bridge that unit change by combining the measured concentration with extract volume, dilution factor, and original sample mass. It also offers recovery adjustment for cases where the extraction process is known to recover less than the full microbial load. That makes the tool useful for food, environmental, feed, fermentation, and general biology workflows.
The result section includes wet-basis CFU/g, recovery-adjusted CFU/g, and log values for quick review. A graph is also included so you can compare the entered liquid concentration with the converted solid-basis results. Use the example table to test the logic before applying your own laboratory numbers.
It converts a microbial concentration reported as CFU/mL into CFU/g. The calculation uses extract volume, original sample mass, and any extra dilution applied before measurement.
It links the liquid measurement back to the total suspension prepared from the weighed sample. Larger extract volumes raise the converted CFU/g value when everything else stays unchanged.
Use the total extra dilution applied after homogenization and before measurement. Enter 1 when no additional dilution occurred. A 1:100 dilution should be entered as 100.
Recovery factor adjusts for incomplete organism recovery from the sample matrix. Enter 100 when no correction is needed. Lower percentages increase the recovery-adjusted CFU/g estimate.
Yes, but the output remains CFU/g based on the mass you enter. For dry-basis work, enter the equivalent dry mass or calculate moisture correction separately.
The converted CFU/g will also be zero for the entered setup. Log values are not shown because logarithms of zero are undefined.
No. It is a calculation aid, not a substitute for validated methods, plating protocols, or regulatory reporting rules used by your laboratory.
Wet-basis CFU/g equals CFU/mL multiplied by extract volume and dilution factor, then divided by sample mass. Recovery-adjusted CFU/g divides that result by recovery fraction.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.