Enter the percent DNA fragmentation result from your semen lab report and choose the test method to see a clear risk category, the cutoffs used, and what to ask next. If your lab provides its own reference range, you can use it here so the category matches your report.
Advanced options
How to use our Sperm DNA Fragmentation Risk Calculator
- Find the DNA fragmentation percent on your lab report (often called DFI) and enter it in "DNA fragmentation result (percent, %)."
- Select the "Test method (assay)" if your report lists it (for example SCSA, TUNEL, or Comet). If you are not sure, choose "Not sure."
- Choose "Use my lab's reference cutoffs?" Select Yes if your report shows its own cutoffs (like "normal < 20%").
- If you chose Yes, open "Advanced options" and enter your lab cutoff for low risk and high risk exactly as written on your report.
- (Optional) Pick "How are you trying to conceive" to get notes that match your situation (timed intercourse, IUI, IVF, or ICSI).
- (Optional) If your report is SCSA and lists HDS, enter it in "SCSA HDS" for extra context.
- (Optional) Choose a rounding setting if you want fewer or more decimals in the displayed numbers.
- Click "Calculate" to see your risk category, the exact cutoffs used, and a short list of questions to bring to a clinician.
Definitions
DNA fragmentation (SDF): Breaks or damage in sperm DNA measured by a lab test. It is usually reported as a percent.
DFI (DNA Fragmentation Index): A common name for the percent result, especially on SCSA reports [3].
Assay (test method): The lab technique used to measure DNA damage (for example SCSA, TUNEL, or Comet). Different methods can produce different percent values for the same sample.
Cutoff (threshold): A percent value used to split results into categories like low, moderate, or high risk.
Lab reference range: The cutoffs your specific lab provides for interpreting the result. Labs may set their own ranges [2].
SCSA: A flow cytometry based sperm DNA test that often reports DFI and may report HDS [3].
HDS (High DNA Stainability): An SCSA output that can relate to immature sperm chromatin; not every report includes it [3].
Methodology
What this calculator does
This tool classifies a DNA fragmentation percent into a simple risk category (low, moderate, or high). It uses either (1) your lab's own cutoffs if you choose to enter them, or (2) method-based default cutoffs if you do not. The goal is clarity and consistency, not a medical decision.
Inputs and validation
The DNA fragmentation value must be a percent from 0 to 100. A test method selection is required. If you choose to use lab reference cutoffs, then both lab cutoffs are required and must satisfy: 0 to 100, and low cutoff is less than high cutoff. Optional fields (trying method, HDS, rounding) can be left blank; if you type a value, it must be a valid number.
Category rules (the math)
When using your lab reference cutoffs: If value is less than your low cutoff, category is Low risk. Else if value is greater than or equal to your high cutoff, category is High risk. Otherwise, category is Moderate risk.
When not using lab cutoffs (method defaults): The calculator uses these default thresholds: SCSA/DFI: low is less than 15, moderate is 15 to 30, high is 30 or more. TUNEL: low is less than 20, high is 20 or more. Comet: low is less than 14, high is 14 or more. If method is Not sure, it uses the SCSA style three-band cutoffs (less than 15, 15 to 30, 30 or more) and labels the result as a rough estimate.
Why the method and cutoffs can differ
Different assays measure DNA damage in different ways, so their percent results and common cutoffs are not interchangeable. Also, major references emphasize that universal cutoffs are not guaranteed, and labs may establish their own reference ranges and reporting language [2]. That is why this calculator highlights the cutoffs used and strongly encourages using your own report's reference values when available.
How the optional context notes are chosen
The "trying to conceive" selection does not change your category. It only changes the wording of the educational notes shown with your result (for example, general notes for timed intercourse or IUI, and different context for IVF or ICSI). Many factors besides DNA fragmentation can affect outcomes, so the notes are intentionally short and paired with questions to discuss with a clinician [1].
How HDS is handled
If you enter HDS, the calculator displays it and adds a note that HDS is typically reported with SCSA and should be interpreted in the context of the full report [3]. It does not convert HDS into a separate risk score.
Edge cases and safety behavior
Values of 0 or 100 are allowed but trigger a reminder to double-check that the number was copied correctly. If inputs are invalid (missing method, percent outside 0 to 100, or lab cutoffs that do not satisfy low less than high), the calculator shows a clear error and does not produce results.