a dietetic practice group of the
Diabetes Care
and Education
Advanced Insulin Management: Using
Insulin-to-Carb Ratios and Correction Factors
A nutrition resource for living well with diabetes
* American Diabetes Association
If you are using background and
meal-time insulin therapy (longacting
insulin + rapid-acting insulin or on an
insulin pump), you may benet from
using an insulin-to-carbohydrate ratio
and a blood glucose correction factor
to determine your meal-time insulin
dose. Learning to adjust your insulin
dose to the amount of food you eat
provides exibility with eating. It
requires a good understanding of
your medicines and carbohydrate or
“carb” counting.
What Is An Insulin-to-
Carb Ratio?
An insulin-to-carb ratio helps you
dose how much rapid-acting insulin
you need to “cover” the carbohydrate
you will eat at a meal or snack. For
example, some people might take
1.5 units for every carb choice, or
others might take 1 unit for every 10
grams of carb. Your health care
provider or registered dietitian —
who may also be a certied diabetes
educator (CDE) — can help you
choose a starting ratio; however, it
may take experimentation before you
nd the correct insulin-to-carb ratio
for you. Records of what you ate, the
estimated amount of carbohydrate in
your meal, how much insulin you took,
and what your blood glucose was
before and two hours after you ate will
help you decide if the ratio is correct,
or if it should be adjusted. Dierent
people have dierent insulin-to-carb
ratios. Additionally, insulin-to-carb
ratios may change over the course of
your lifetime or even throughout the
day. Some people have one ratio for
breakfast and a dierent ratio for
lunch and dinner.
What Is An Insulin
Correction Factor?
The insulin correction factor
(sometimes called an insulin
sensitivity factor) is used to calculate
the amount of insulin you need to
bring your blood glucose into target
range. This adjusts or corrects a blood
glucose level that may be higher or
lower than desired before a meal.
The correction dose is added to,
or subtracted from, the pre-meal
insulin dose. For example, some
people might take 1 unit
if blood glucose is
50 mg/dL higher than
the target, and others
might take 1 unit for every 25 mg/dL
higher than the target.
Your health care provider will help you
determine your insulin correction
factor as you begin working with this.
Target Blood
Glucose Range
Your health care provider should give
you individualized guidelines for what
your blood glucose range should be for
safety and good health.
Example pre-meal target range*:
70-130 mg/dl
Example post-meal target range*:
Less than 180 mg/dl
(two hours after rst bite)
Putting it all together
Step 1: Calculate an insulin dose for food:
1. Add up the grams of carbohydrate in the foods you
will eat.
2. Divide the total grams of carb by your insulin-to-carb ratio.
Total Grams Of Carbohydrate to be Eaten
Insulin-to-Carb Ratio
Example
Let’s say you plan to eat 45 grams of carbohydrate and your
insulin-to-carb ratio is 1 unit of insulin for every 15 grams of
carbohydrate eaten. To gure out how much insulin to give,
divide 45 by 15.
45 Grams Of Carbohydrate
15
= 3 units of insulin is needed for this amount of carbohydrate
Step 2: How to use your correction factor to
reach your target blood glucose
1. Subtract your target blood glucose from your current
blood glucose.
2. Divide the dierence by your correction factor.
Current Blood Glucose – Target Blood Glucose
Correction Factor
Example:
You check your pre-meal blood glucose and it is
190 mg/dl, and your target blood glucose is 120 mg/dl.
Your insulin correction factor is 35.
190 mg/dl – 120 mg/dl
35
= 2 units of insulin will bring blood
glucose of 190 mg/dl down to
120 mg/dl.
Step 3: Add the insulin needed for carbs to the
insulin to correct high blood glucose
for your total dose:
Example from steps 1and 2:
3 units for food (carbs)
+ 2 units to correct high blood glucose
Total Dose = 5 units
Avoid causing low blood glucose! Follow the advice of your
health care provider or registered dietitian regarding when to
correct your blood glucose. Most people correct their blood
glucose only before meals, not between meals.
Your current insulin plan
Long-acting:
Dose a.m.___________ p.m.___________
Your new insulin plan:
1. Insulin-to-carb ratio:
You will need 1 unit of rapid-acting or short-acting insulin
for each _____ grams of carb
2. Blood glucose correction factor (insulin to correct high
blood glucose*):
1 unit of rapid-acting or short-acting insulin for each
______ points (mg/dl) your blood glucose level is over
target of ______ mg/dl
3. Your pre-meal target blood glucose:
__________ mg/dl
* Discuss when to correct for low blood glucose with your health care
provider.
Registered dietitians (RD) do not have prescriptive authority.
Rapid-acting or short-acting:
Dose B _________ L _________ D _________
Other _________
Total units of insulin
per day__________
= Correction Dose
© 2013 Diabetes Care and Education Dietetic Practice Group. Permission
to reproduce for non-prot educational purposes granted through 2015.
Educational grant provided by Abbott Diabetes Care. The company has
had no inuence on the content of this educational handout.
For more information contact the Academy of Nutrition and Dietetics at
www.eatright.org.
Step 1: Calculate an insulin dose for food:
1. Add up the grams of carbohydrate in the foods you
will eat.
2. Divide by your insulin-to-carb ratio
Total Grams of Carbohydrate to be Eaten
Insulin-to-Carb Ratio
Step 2: How to use your correction factor to
reach your target blood glucose:
1. Subtract your target blood glucose from your current
blood glucose.
2. Divide the dierence by your correction factor.
Current Blood Glucose – Target Blood Glucose
Correction Factor
Step 3: Add the insulin needed for carbs to the
insulin to correct high blood glucose for your
total dose:
Now, it’s your turn! Practice using your information.
Practice:
Let’s say you plan to eat 60 grams of carbohydrate and your
insulin-to-carb ratio is 1 unit of insulin for every _____ grams
of carbohydrate eaten. To gure out how much insulin to
give, divide 60 by _____.
60 Grams of Carbohydrate to be Eaten
_____
= _____ Units Of Insulin For Food (carbs)
Practice:
You check your blood glucose and it is 250 mg/dl, and you
know your target blood glucose is _____ mg/dl. Your insulin
correction factor is _____.
250 mg/dl – _____ mg/dl
_____
= ____ units of insulin will bring blood glucose of
250 mg/dl down to your target blood glucose of _____.
Practice:
Example from steps 1and 2:
_____ Units for food (carbs)
+ _____ Units to correct high blood glucose
Total Dose = _____ Units
Work with your health care provider or a registered dietitian to help you
ll in this worksheet. Your correction factor can change over time.
Blood Glucose Range Units of Insulin to
Correct the BG
1
2
3
4
5
Advanced Insulin Management:
Calculation Worksheet
= Correction Dose