Establishing Starting Basal and Bolus Dosing
Based on Pre-Meal Readings and Carb Counting
Determining the starting Carb Ratio and
Correction Factor
Total Daily Dose
Split to mimic Euglycemic control
50%
Basal
50%
Bolus
500 Rule: 500 divided by TDD
Example: 500 / 50 = 10
Insulin to carb ratio = 1u for 10g
Insulin Sensitivity or Correction Factor
1800 rule Humalog/Novolog/Apidra
1800 divide by TDD= mg/dl drop in BG
Example: 1800/50 = 36 mg/dl
Insulin sensitivity ratio = 1u for 36mg/dl
1500 rule Regular Insulin
1500 divide by TDD=mg/dl drop in BG
Example: 1500/50 = 30 mg/dl
Insulin sensitivity ratio = 1u for 30mg/dl
Ms. Johnson has A1c of 7.6 and is on
 Glargine (Lantus) 60 units at bedtime
 Lispro(Humulog) sliding scale with
average daily dose of 30 units
 Usually takes 3 correction shots based on
pre-meal readings: If BG is





120-150 - 3 units
151-180 - 5units
181-210 - 7units
211-240 - 9units
241-270 -11units
Ms. Johnson’s starting Glargine dose is
45 units
Her total daily dose is 90 units and using the
50/50 ratio her basal dose would be 45
units.
Her target should be established at no
more than 50 mg/dl below average BG
A1c 7.6 = average bg of 170mg/dl
Target could be 120 mg/dl
Ms. Johnson’s sensitivity to 1 unit of Rapid
Acting insulin will be: 20 mg/dl
Using the 1800 rule for rapid insulin as
described: 1800/90= 20 mg/dl
Ms. Johnson’s carb ratio to 1unit of Rapid
Acting Insulin will be 5 carbs
Using the 500 rule for rapid insulin as
described: 500/90= 5 carbs
Ms. Johnson’s pre-lunch reading is 220 mg/dl
and she is going to eat 70 carbs her dose of
Apidra would be:
Carb ratio is 5carbs/unit so 70/5 =14
1. 5 units
units for food
2. 14 units
Sensitivity is 20mg/dl/unit to a target of
120 so 220mg/dl -120mg/dl =100 mg/ dl
3. 16 units
so 100/20= 5 units for correction
4. 19 units
14 units for food
5. 23 units
+5 units for correction
19 units total needed