Phosphorus levels: what's normal, high and low
A mineral that, with calcium, builds bones and teeth and supports many cellular processes.
Medically reviewed by Youmna DiStefano, MD · Last reviewed September 2026
The short answer
Phosphorus is measured with a standard blood draw; no fasting is needed. A typical reference range is 2.50 – 4.50 mg/dL. At TestWell it's $23.99 all-in as Renal Panel, results in 2–4 business days, drawn at Quest or Labcorp. An out-of-range result is a prompt to look closer, not a diagnosis.
- Units
- mg/dL
- Sample
- Blood draw
- Fasting
- Not required
- Results
- 2–4 business days
- Price
- $23.99
- Labs
- Quest or Labcorp
Phosphorus Reference Range
These are the typical adult reference ranges used by major US labs. Your report will include the specific range used by the lab that processed your sample.
| Population | Range |
|---|---|
| age 18+ | 2.50 – 4.50 mg/dL |
Reference ranges are educational. Always interpret your result with the specific range printed on your lab report and discuss anything outside the range with a clinician.
What your Phosphorus result may mean
Often reflects kidney impairment or excess vitamin D.
What a high Phosphorus means: causes, symptoms, next steps →Can reflect poor nutrition, alcohol use, or certain medications.
What a low Phosphorus means: causes, symptoms, next steps →Educational only — not a diagnosis. Many factors can influence a single result. Discuss anything that concerns you with a healthcare provider.
How do you get a Phosphorus test?
Order online, a licensed physician reviews the requisition, and you walk into a nearby lab for the draw. Phosphorus is available on its own or inside these panels — panels cost less per marker when you want the fuller picture.
| Option | Includes | Price |
|---|---|---|
| Renal Panel | This marker only | $23.99 |
| Kidney Health Panel | 4 tests | $64.99 |
| Total Body Panel | 49 tests | $499.99 |
Quest vs. Labcorp for Phosphorus: which lab should you pick?
Both are CLIA-certified national labs and the result is clinically equivalent, so pick whichever location is closer. Your report will print that lab's own reference range, which can differ slightly from the table above.
| Lab | Available | Price |
|---|---|---|
| Quest Diagnostics | Yes | $23.99 |
| Labcorp | Yes | $23.99 |
| BioReference (NY & NJ) | No | — |
Need help choosing a location? Use the lab finder to see draw sites near your ZIP.
Frequently asked
Often reflects kidney impairment or excess vitamin D. A single result above the reference range is a prompt to look closer with a clinician — often a repeat test and related markers — not a diagnosis on its own.
Ready to test your phosphorus?
Order in two minutes, get physician-approved, and visit a lab the same day. Starts at $23.99.