Glycemic Index Calculator - Calculate GI & Glycemic Load

Calculate the glycemic index (GI) and glycemic load (GL) of foods and meals to manage blood sugar levels, control diabetes, and optimize nutrition for better health

Updated: November 2025 • Free Tool

Glycemic Index & Load Calculator

1 = standard serving, 2 = double serving, etc.

Your Results

Glycemic Index (GI)
55
Medium GI
Glycemic Load (GL)
16.5
Medium GL
Blood Sugar Impact
Moderate blood sugar rise. Suitable for most people in controlled portions.
Total Carbs 30g
Serving Size 1x
Recommendation
Pair with protein or healthy fats to slow glucose absorption.

What is a Glycemic Index Calculator?

A Glycemic Index Calculator is a free nutrition tool that helps you determine the glycemic index (GI) and glycemic load (GL) of foods and meals. It calculates how quickly foods raise blood sugar levels, helping you make informed dietary choices for blood sugar management, diabetes control, and weight management.

This calculator helps you:

  • Calculate GI & GL - Determine blood sugar impact of foods and meals
  • Manage diabetes - Control blood glucose levels with smart food choices
  • Optimize energy - Choose foods for sustained energy without crashes
  • Support weight loss - Select low-GI foods that promote satiety and fat burning

To calculate your daily calorie needs for weight management alongside GI tracking, check out our TDEE Calculator to determine your Total Daily Energy Expenditure based on activity level.

For planning balanced macronutrient intake with low-GI foods, explore our Macronutrient Calculator to calculate optimal protein, carbs, and fats for your health goals.

To track nutrition in your meals and ensure low-GI choices, use our Meal Calorie Calculator to calculate total calories and macros with precise serving sizes.

For managing blood sugar levels and cardiovascular health, try our Blood Pressure Calculator to assess your cardiovascular risk and get health recommendations.

To optimize your overall diet for health and weight management, check our BMI Calculator to determine if you're at a healthy weight and need dietary adjustments.

How the Glycemic Index Calculator Works

The calculator uses established formulas to determine blood sugar impact:

Glycemic Index (GI)
Measures how quickly a food raises blood sugar compared to pure glucose (GI = 100)
Glycemic Load (GL) Formula
GL = (GI × Carbohydrates in grams) ÷ 100
Example Calculation
Watermelon: GI = 72, Carbs = 11g
GL = (72 × 11) ÷ 100 = 7.9 (Low GL)

GI Categories:

  • Low GI (55 or less): Slow, steady blood sugar rise
  • Medium GI (56-69): Moderate blood sugar impact
  • High GI (70+): Rapid blood sugar spike

GL Categories:

  • Low GL (10 or less): Minimal blood sugar impact
  • Medium GL (11-19): Moderate impact
  • High GL (20+): Significant blood sugar rise

Understanding GI & GL

Glycemic Index

Measures the quality of carbs - how quickly they raise blood sugar. Pure glucose = 100. Lower is better for blood sugar control.

Glycemic Load

Considers both quality (GI) and quantity (carbs). More accurate for real-world impact. Accounts for serving size.

Blood Sugar Response

Low-GI foods cause gradual rise, sustained energy. High-GI foods spike blood sugar, followed by crashes.

Insulin Impact

High-GI foods trigger insulin spikes, promoting fat storage. Low-GI foods support stable insulin and fat burning.

How to Use This Calculator

1

Select Food

Choose from common foods or enter custom GI value

2

Enter Carbs

Input carbohydrate amount in grams per serving

3

Adjust Serving

Set serving size multiplier if needed (1x, 2x, etc.)

4

View Results

See GI, GL, blood sugar impact, and recommendations

Benefits of Using GI Calculator

  • Better Blood Sugar Control: Choose low-GI foods to maintain stable glucose levels and prevent spikes that damage health.
  • Diabetes Management: Make informed food choices to control blood sugar, reduce medication needs, and prevent complications.
  • Sustained Energy: Low-GI foods provide steady energy without crashes, improving focus and physical performance throughout the day.
  • Weight Management: Low-GI foods increase satiety, reduce cravings, and promote fat burning by stabilizing insulin levels.
  • Heart Health: Low-GI diets reduce cardiovascular disease risk by improving cholesterol, blood pressure, and inflammation markers.

Factors That Affect Glycemic Response

1. Food Processing

Refined and processed foods have higher GI. Whole grains, fiber-rich foods have lower GI due to slower digestion.

2. Ripeness & Cooking

Riper fruits have higher GI. Cooking increases GI by breaking down starches. Al dente pasta has lower GI than soft pasta.

3. Food Combinations

Adding protein, fat, or fiber lowers meal GI. Vinegar and lemon juice also reduce glycemic response significantly.

4. Individual Factors

Age, insulin sensitivity, gut health, and physical activity affect personal glycemic response to the same foods.

Glycemic Index Calculator - Free online tool to calculate GI and glycemic load of foods for blood sugar management with instant results
Professional glycemic index calculator interface for determining GI and GL values of foods. Features include food selection, custom GI input, carbohydrate tracking, serving size adjustment, and instant blood sugar impact analysis with mobile-friendly design.

Frequently Asked Questions (FAQ)

Q: What is a Glycemic Index Calculator?

A: A Glycemic Index Calculator is a tool that helps you determine the glycemic index (GI) and glycemic load (GL) of foods and meals. It calculates how quickly foods raise blood sugar levels, helping you make informed dietary choices for blood sugar management, diabetes control, and weight management.

Q: What is a good glycemic index?

A: Low GI foods (55 or less) are best for blood sugar control and sustained energy. Medium GI foods (56-69) should be eaten in moderation. High GI foods (70 or above) cause rapid blood sugar spikes and should be limited, especially for people with diabetes or insulin resistance.

Q: What is glycemic load and how is it different from GI?

A: Glycemic Load (GL) considers both the quality (GI) and quantity (carbs) of food. GL = (GI × Carbs) ÷ 100. While GI measures how quickly food raises blood sugar, GL shows the actual impact based on serving size. A low GL is 10 or less, medium is 11-19, and high is 20 or more.

Q: Can I eat high-GI foods if I have diabetes?

A: High-GI foods should be limited but not completely avoided. Pair them with protein, healthy fats, or fiber to lower the overall meal GI. Control portions and monitor blood sugar response. Focus on low-GI foods as your dietary foundation.

Q: How do I calculate glycemic load?

A: To calculate glycemic load: GL = (GI × Carbohydrates in grams) ÷ 100. For example, watermelon has a high GI of 72, but only 11g carbs per serving, giving a GL of 7.9 (low). This shows that serving size matters as much as GI value.

Q: Do low-GI foods help with weight loss?

A: Yes, low-GI foods promote weight loss by increasing satiety, reducing hunger, stabilizing blood sugar, and preventing insulin spikes that promote fat storage. They provide sustained energy for exercise and daily activities without crashes.

Q: How does cooking affect glycemic index?

A: Cooking generally increases GI by breaking down starches and making them easier to digest. Al dente pasta has lower GI than soft pasta. Cooling cooked starches (like rice or potatoes) can lower GI by forming resistant starch.

Q: What foods have the lowest glycemic index?

A: Non-starchy vegetables (broccoli, spinach, peppers), legumes (lentils, chickpeas), most fruits (berries, apples, pears), nuts, seeds, whole grains (quinoa, barley), and dairy products typically have low GI values under 55.