Input Data
Enter time (minutes) and capillary glucose (mmol/L or mg/dL) for the reference and one or more test replicates.
time,value rows below.Reference data
| Time (min) | Glucose |
|---|
Test data (replicates)
| Time (min) | Glucose |
|---|
| Replicate | IAUC Test | GI |
|---|---|---|
| Mean ± SD | — | — |
Curve plot
Formula used
Glycemic Index (GI) is computed as:
GI = 100 × IAUC(test) / IAUC(reference)
- IAUC: Incremental area via trapezoids within the chosen window.
- Area below fasting baseline optionally ignored.
- Linear interpolation fills gaps between time points.
- White bread results optionally converted to a glucose scale.
GL = (GI / 100) × available carbohydrates per serving.
How to use this calculator
- Enter reference and test series; add replicates if needed.
- Set analysis window, baseline, and interpolation preferences.
- Choose scale and conversion factor when using white bread.
- Click Compute GI to view IAUC, GI, GL, and stats.
- Export summaries as CSV or PDF for reporting.
Suggested sampling: 0, 15, 30, 45, 60, 90, 120 minutes.
Example data table
Use the button to preload representative values and replicates.
| Time (min) | Reference | Test |
|---|---|---|
| 0 | 5.0 | 5.0 |
| 15 | 6.2 | 5.7 |
| 30 | 7.4 | 6.3 |
| 45 | 7.0 | 6.1 |
| 60 | 6.3 | 5.8 |
| 90 | 5.5 | 5.3 |
| 120 | 5.1 | 5.1 |
Glycemic Index quick data
1) GI categories
| Category | GI range (glucose scale) |
|---|---|
| Low GI | < 55 |
| Medium GI | 55–69 |
| High GI | ≥ 70 |
2) Sample GI of common foods
| Food | Approx. GI |
|---|---|
| Glucose (reference) | 100 |
| White bread | ~75 |
| Cornflakes | ~81 |
| Baked potato | ~78 |
| Apple | ~36 |
| Lentils | ~32 |
3) Factors affecting GI
- Ripeness, particle size, and cooking method.
- Presence of fat, protein, and fiber slows absorption.
- Food processing and starch type (amylose vs amylopectin).
- Serving temperature and resistant starch formation.
4) GI vs GL reference
GL = (GI / 100) × available carbohydrates per serving.
| GL category | GL per serving |
|---|---|
| Low GL | ≤ 10 |
| Medium GL | 11–19 |
| High GL | ≥ 20 |
Frequently Asked Questions
1) What is the Glycemic Index?
The Glycemic Index ranks carbohydrate foods by how quickly they raise blood glucose compared with a reference food. Lower values indicate slower digestion and absorption, leading to a more gradual blood sugar response after eating.
2) How do you calculate IAUC here?
We use trapezoidal integration across the selected time window. When enabled, values below the fasting baseline are ignored. Optional smoothing reduces noise. Interpolation connects sampling gaps to approximate the curve between measured time points.
3) What is the difference between GI and GL?
GI reflects carbohydrate quality by comparing blood glucose responses. GL combines quality and quantity: GL = (GI/100) × grams of available carbohydrates in a serving. A small portion can have low GL even when GI is moderate.
4) Can I mix mg/dL and mmol/L?
The calculator converts mg/dL to mmol/L internally. However, mixing units within the same series can introduce errors. Choose one unit per series for consistent IAUC and GI results, then repeat with conversions if comparison is required.
5) What sampling schedule should I use?
Common research schedules include 0, 15, 30, 45, 60, 90, and 120 minutes. More points improve accuracy. Keep identical schedules for test and reference foods to ensure consistent IAUC and GI comparisons across replicates.