Based on serving
Blood Glucose Response Chart
The Glycemic Load (GL) calculator is a tool that estimates in real-time how much a specific food will raise your blood sugar levels, taking into account both the Glycemic Index (GI) (how quickly carbs affect blood sugar) and the amount of carbohydrates in a serving.
It helps people, especially those managing diabetes or diets, predict the impact of foods on their glucose levels more accurately than the Glycemic Index alone.
The GL Calculation Formula:
GL = (GI x Grams of Carbohydrates per Serving) / 100
Take the Glycemic Index (GI), multiply it by the carbs in a serving, then divide by 100 to get the Glycemic Load.
Glycemic Load calculation is a quick way to see how both the speed and amount of carbs in your food hit your glucose levels.
Below the calculator, there’s an Interactive Blood Glucose Chart displaying the Glycemic Impact based on the Glycemic Load calculated for your food. The chart is tailored to metabolic factors such as normal, pre-diabetic, and diabetic conditions, helping you visualize how different foods might affect your glucose levels based on your specific health profile.
To calculate Glycemic Load (GL), you need two variables:
- Glycemic Index (GI) of the food
- Total Digestible/Available Carbohydrates in serving (Total Carbohydrates minus sugars, starches, and dietary fibers)
Glycemic Index (GI)
The Glycemic Index (GI) is a scale from 0 to 100 that measures how quickly a carbohydrate-containing food raises blood sugar levels after consumption.
Foods with a high GI, like white bread or sugary snacks, cause rapid spikes, while low-GI foods, such as lentils or most vegetables, result in a slower, more gradual increase. The GI scale is based on comparing foods to pure glucose, which has a GI of 100, providing insight into how different carbohydrates affect the body’s energy levels and insulin response.
However, Glycemic Index alone does not tell the full story.
Read more: Glycemic Index: Simple Science, Complex Controversy
While GI reflects how fast blood sugar rises, it does not account for how much it rises - which depends on the amount of carbohydrates consumed. This is where Glycemic Load (GL) comes in.
Glycemic Load calculation provides a more accurate measure of a food’s impact by incorporating both GI and portion size.
For example, watermelon has a high GI (72), but because it contains very little carbohydrate per serving, its GL is low (4 per 100g), meaning it has a minimal overall effect on blood sugar.
By using both Glycemic Index and Glycemic Load, you can make better dietary choices, balancing the speed and intensity of blood sugar changes to support energy stability, weight management, and diabetes control.
Why Portion Size Matters?
Portion size determines the amount of carbs you eat, which the Glycemic Load (GL) calculation uses. GL multiplies a food’s Glycemic Index (GI) by the carbs in a serving, then divides by 100. A small portion of high-GI watermelon (GI 72) has a low GL with few carbs, while a big serving of low-GI pasta (GI 45) can have a high GL due to more carbs. It’s the serving size that makes GL a better gauge of blood sugar impact.
It’s the serving size that makes GL a better gauge of blood sugar impact. But the type of carbohydrates matters too. Total available carbohydrates refine this further by focusing only on the carbohydrates that actually affect your glucose, tying directly into the GL formula.
Digestible Carbohydrates and Glycemic Load
Total digestible carbohydrates are the total carbohydrates in a food minus the fiber and, in some cases, sugar alcohols like erythritol, because these don’t get fully digested or spike blood sugar like other carbs do. In the Glycemic Load (GL) calculation - where you multiply a food’s Glycemic Index (GI) by the carbs in a serving and divide by 100 - using total available carbohydrates sharpens the accuracy of how much a food will really affect your glucose levels.
For instance, if a food has 25g total carbohydrates, including 6g fiber and 4g sugar alcohols, the total available carbohydrates is 15g (25 - 6 - 4, depending on how sugar alcohols are counted).
Plugging that 15g into the GL formula gives a truer sense of its blood sugar impact.
This matters especially for low-carb or keto diets, where fiber-heavy foods like nuts or veggies can look high in carbohydrates but have a much lower total available carbohydrates count, making GL a practical tool for managing insulin and energy without overestimating carb effects.
Glycemic Load Calculation
The Glycemic Load (GL) calculation tells you how much a specific serving of food will affect your blood sugar by combining its Glycemic Index (GI) with the amount of carbs you’re eating. The formula is simple: multiply the GI (a number from 0 to 100 showing how fast carbs raise blood sugar) by the grams of carbohydrates in a serving, then divide by 100.
For example, if a food has a GI of 50 and a serving contains 20g of carbs, the GL is (50 × 20) ÷ 100 = 10. A GL below 10 is low, 11-19 is medium, and 20 or higher is high.
Using total digestible carbohydrates (total carbs minus fiber and sometimes sugar alcohols) makes it even more precise, especially for foods with lots of fiber, giving you a practical snapshot of how your glucose will respond to what’s on your plate.