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 benet 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 certied 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. Dierent
people have dierent 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 dierent 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)