PK Noncompartmental Analysis
AUC · Cmax · Tmax · t½ · CL/F · Vz/F
PK Noncompartmental Analysis
AUC · Cmax · Tmax · t½ · CL/F · Vz/F
Calculated locally in this browserColumn order: time_h, concentration
Editable data table
| time_h | concentration | |
|---|---|---|
Paste CSV / TSV
Analysis result
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PRACTICAL GUIDE
Use the result with confidence.
Use this noncompartmental analysis calculator to summarize a concentration–time profile with AUC₀–t, extrapolated AUC₀–∞, Cmax, Tmax, terminal half-life, apparent clearance and volume. The selected terminal-point count and regression fit remain visible because extrapolated exposure depends on the terminal phase.
Open the calculatorCheck the calculation in context.
Single-dose profile with a supported terminal phase
How is AUC₀–∞ separated from observed exposure?
- Sort valid concentrations by time and integrate through the last measurable observation.
- Fit the predefined positive terminal concentrations on the log scale.
- Add the final observed concentration divided by the terminal rate constant.
Result
AUC₀–∞ equals observed AUC₀–t plus the extrapolated tail area.
Interpretation: Report the extrapolated fraction and terminal regression diagnostics; a computed value is not reliable when the terminal phase is poorly supported.
Terminal points changed from three to four
Why can half-life and clearance change?
- The terminal slope is estimated from the selected late observations.
- Adding a distribution-phase point can steepen or flatten that slope.
- AUC extrapolation, half-life, clearance and volume therefore change together.
Result
Terminal-point selection is an analysis decision, not a cosmetic setting.
Interpretation: Use a prespecified selection rule and inspect the concentration–time profile rather than choosing points solely for the highest R².
Correct numbers can still lead to a poor experiment.
Using unsorted or duplicate times without review
NCA integration assumes an interpretable time sequence, and replicate handling changes the profile.
What to do
Apply the study-defined replicate and below-quantification rules before analysis, then verify chronological order.
Selecting terminal points only by R²
A high R² can still describe distribution rather than terminal elimination.
What to do
Use pharmacological context, visual inspection and a prespecified minimum terminal span in addition to regression diagnostics.
Ignoring dose and unit consistency
Clearance and volume inherit the units of dose, time and concentration.
What to do
Document dose basis, bioavailability interpretation and every input unit before reporting derived parameters.
REPORTING NOTES
Document the calculation clearly.
Copy a methods-ready sentence or preparation checklist, then adapt it to your actual protocol, instrument and acceptance criteria.
Methods sentence
Noncompartmental analysis used the stated trapezoidal convention and a prespecified set of terminal positive concentrations for log-linear regression.
Result sentence
Report dose and route, concentration and time units, AUC₀–t, AUC₀–∞, extrapolated fraction, Cmax, Tmax, terminal slope, half-life, regression diagnostics and apparent clearance or volume notation.
Questions researchers often ask.
What is the difference between AUC0-t and AUC0-infinity?
AUC₀–t integrates observed exposure through the last measurable concentration. AUC₀–∞ adds an estimated terminal tail and is more dependent on terminal-phase support.
How many terminal points should be used?
At least three positive observations are generally needed to fit a line, but the correct selection depends on the prespecified analysis rule, sampling design and whether the points represent terminal elimination.
Does the calculator handle BLQ values automatically?
No universal BLQ rule is imposed. Apply the study-specific below-quantification and missing-data procedure before entering the analysis dataset.
Are clearance and volume absolute after extravascular dosing?
Without known bioavailability, they are typically apparent parameters such as CL/F and Vz/F. Route and dose interpretation must be reported.
Data requirements
Enter at least 2 time points with non-negative numeric concentrations.
time_h, concentrationReview before reporting
Research use only. Validate raw data, exclusions and interpretation against the approved analysis plan.
Check raw observations, excluded rows, model assumptions and study-specific acceptance criteria before using the result.
Transparent analysis
Inputs are processed locally in your browser. Review the calculation policy, limitations and verification approach before reporting a result.
Read the methodology →EVIDENCE & REVIEW
A result you can audit.
Reviewed 12 August 2026AUC and terminal-phase calculation review complete
Implementation check
The workflow sorts concentration-time observations, applies linear trapezoids and exposes terminal regression fit before deriving half-life, AUC extrapolation, apparent clearance and volume.
Interpretation boundary
NCA results depend on sampling coverage, BQL rules, dose and route definitions, terminal-point selection and the suitability of log-linear extrapolation. Confirmatory work requires the approved analysis environment.
Method references
M13A Bioequivalence for Immediate-Release Solid Oral Dosage FormsU.S. FDA / ICHNoncompartmental PK parameters, terminal-phase estimation and AUC reporting context.
REFERENCE VALIDATION CASE
Linear trapezoid exposure
(10+5)/2 × 1 + (5+2.5)/2 × 1.
Inputs
- Time: 0, 1, 2 h
- Concentration: 10, 5, 2.5
- Linear trapezoids
Expected result
- Cmax = 10
- Tmax = 0 h
- AUC₀–last = 11.25 concentration·h
Scope: Terminal regression and extrapolated parameters need adequate later samples.
Review and correction history
12 August 2026 · Internal implementation review
AUC and terminal-phase calculation review complete. Formula behavior, unit handling, limitations and linked references were checked internally.
Independent reviewer: Not yet published. A name, relevant qualification, date and exact scope will appear here only after a real review is completed.
Source-informed and internally checked; independent scientific or regulatory validation is not claimed. Research use only.