Calculating Your Carbohydrate Ratio

Your carbohydrate ratio determines how much insulin to use for a given amount of carbohydrate. It can vary, particularly in the morning, where you generally require more insulin for the same amount of carbs compared to the rest of the day.

Calculating how much insulin you need for a given amount of carbohydrate is quite easy. Just enter the carbs you have for each meal, and the corresponding amount of insulin below.

Step 1. Enter Current Values

Food measurements


Meal name How many carbs? How much insulin?   Carbohydrate ratio is:
Morning tea  
Afternoon tea  

Step 2. Review

Now you need to check if your ratios are right.

If you get low after breakfast (test 2-3 hours after), then you are getting too much insulin. You need to increase the amount of carbs covered by easy unit, try increasing by 1 or 2 grams, and then test with the new ratio. However, if you are getting too high after breakfast (test 2-3 hours after), then you need more insulin. Try decreasing by 1 or 2 grams, and then test with the new ratio.

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Available scenarios:

How does Low GI food affect my blood sugar?
Calculating Correction Ratio
Calculating Carbohydrate Ratio
Should I inject before my meal?
Afreeza versus Humalog/Novolog/NovoRapid
Lucy thought she was Low
Undiagnosed versus diagnosed Type 2 diabetic
Diabetes and Blindness

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