# Calculator

Community Member
• A Simple Insulin Dosage Calculator

By Neil Bason, Managing Director of Thorpe Products, Ltd. (a Type 1 Caregiver)

For people who inject insulin with a basal/bolus regimen, it's often difficult to calculate the proper pre-meal dose. After watching my partner struggle with the math for fifteen years, I decided to design a simple calculator to mimic the mental process that she uses to calculate her meal-time dose of insulin.

To calculate the number of meal-time insulin units to inject, you must establish the following:

1. Blood sugar level (using a blood glucose meter).
2. The grams of carbohydrates consumed, from which you derive the number of insulin units needed to cover that intake.
3. The amount of exercise to be taken post-injection.

The mental process you must undertake to calculate your insulin dose is as follows:

1. Blood Sugar: Suppose your blood sugar reading is 195 and your target blood sugar is 100. Subtracting 100 from 195, you get 95, which is how much you need to lower your blood sugar. One insulin unit lowers your blood sugar by 55 points, so you divide 95 by 55 to get 1.7 is the number of units you need to lower your existing blood sugar.

2. Carbohydrates: Now you have to count carbohydrates to figure out how many additional units of insulin you need to inject to cover your carb intake. If your ratio of insulin to carbs is 1 unit to 10 grams, 60 grams of carbohydrates requires 6 additional units of insulin.

3. Exercise: If post-injection activity is planned, then you need to calculate how much less insulin will be necessary.

The above is the process that you carry out at every meal. The Insulin Unit Calculator merely mimics this process, as follows:

When the calculator is turned on, Blood Sugar appears on the display. You input your blood sugar reading (195) and press the ENTER key. The calculator automatically makes your first calculation: 195 - 100 = 95 ÷ 55 = 1.7.

As soon as the ENTER key is pressed, Carbohydrates appears on the display. You must now mentally calculate the grams of carbohydrates you consumed and then, based on your carb to insulin ratio, calculate the number of insulin units required to cover that carb intake. For example, 60 carbs at a 10:1 ration = 6 units of insulin. You key the number 6 into the calculator and press ENTER again.

Exercise then appears on the display to prompt you to think about upcoming exercise. The calculator offers four options, from zero to three. 0 denotes no exercise, and 3 denotes heavy exercise. If 2 is entered, the calculator subtracts 2 insulin units from the equation.

When the ENTER key is pressed following the exercise input, the calculator automatically makes the total calculation: 195 - 100 = 95 ÷ 55 = 1.7 + 6 = 7.7 - 2 = 5.7 units

The above may look complicated, but using the calculator is really very simple. All you do is the following:

Enter insulin units to compensate for carbohydrates consumed (6)

Enter an exercise value to compensate for exercise (2)

• The calculator displays the insulin units to be injected (5.7 Units)

My partner, who uses her calculator every day, says, "It is such a relief to know that I am calculating all the elements and getting the right number of insulin units to inject. My blood sugar is now much more stable"

Published On: July 23, 2007
• Aug. 26, 2012

I'm not sure which calculator I should  purchase. There are 2 choices. We still do the traditional sliding scale for my 11 yr. old daughter who was diagnosed on April 30th 2012. Sometimes we still take too long calculating everything before she eats. She does Humalog and Lantus. Is there any difference b/w the two calculators or do I need them both?

Thanxs,...

RHMLucky777

I'm not sure which calculator I should  purchase. There are 2 choices. We still do the traditional sliding scale for my 11 yr. old daughter who was diagnosed on April 30th 2012. Sometimes we still take too long calculating everything before she eats. She does Humalog and Lantus. Is there any difference b/w the two calculators or do I need them both?

Thanxs,

Marcie from California

• Anonymous
Aug. 18, 2009

We have a different requirement for our 11 year old child with type 1 diabetes.

We have to calculate the residual dose in the system (last dose times sliding time factor).

The current Blood Sugar less 6 (target level) divided by 2, then less the previous rsidual.

I have done this in Excel and have it at home and school but it is to complicated...

RHMLucky777

We have a different requirement for our 11 year old child with type 1 diabetes.

We have to calculate the residual dose in the system (last dose times sliding time factor).

The current Blood Sugar less 6 (target level) divided by 2, then less the previous rsidual.

I have done this in Excel and have it at home and school but it is to complicated for her to calculate when out with friends etc.

Do you know of any calculator that could be used?

• Aug. 18, 2009

Hi, this is a very rare calculation, can I ask why this needs to be done?

you can see how Calsulin (INsulin Dose Calculator) works on my website: www.thopre-products.com

Regards,

Neil.

• Gil DePaula
Feb. 15, 2010

Hi,

Could you please explain a little better the formula you use to calculate residual insulin?

You can send it the Excel file to my email if you prefer: gjdepaula@hotmail.com

Thanks!

Gil

• Penny Holt
May. 26, 2009

Hi there, great concept. Australin BSL is meassured different, can it convert?

• Aug. 18, 2009

Hi,  we have two versions of Calsulin (Insulin Dose Calculator)  in both mg/dl and mmol/l.  They are both available online - details are on my website: www.thorpe-products.com  links page.

or email me direct at neil@thorpe-products.com

regards,

Neil.

• Mike
Jan. 02, 2009

I read through the article, yet find no link or reference as to where one may purchase this calculator? Is this an idea or is this item actually for sale?

I'm confused.

• Jan. 02, 2009

Hi Mike,

Sorry to not have a reference in the article, I have only just gotten my production calculators delivered, if you would like to have a calculator just reply to me at neil@thorpe-products.com and I will be happy to send you one, they are \$10.0 each pluse shipping \$4.0

Regards,

Neil.

• Aug. 27, 2012

Please go to my web site where you may purchase the Insulin Dose Calculator: www.thorpe-products.com

• Debra
Nov. 11, 2008

Great calculator.  Now is there a calculator that has all the carb info in it (like the Calorie King book) so we can get some help calculating the amount of carbs in each meal without carrying around that book?  Thanks.

• Oct. 12, 2011

list of indian food   cabo value be posted on internet so that this could be helpful in calculating insulin dose maually