Insulin correction (ISF / ICR)
Insulin correction dose arithmetic: correction = (current - target BG) / ISF, plus optional carb coverage.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Current BG
- 250 mg/dL
- Target BG
- 150 mg/dL
- Total daily insulin dose
- 50 units
- ISF rule
- 1800-rule (rapid-acting analogues)
- Carbs to be eaten
- 60 g
- Insulin-to-carb ratio
- 10 g per unit
Result: Correction ~2.8 U + meal 6 U = ~8.8 U total (ISF 36 from the 1800 rule, a rule of thumb).
The tool opens with these values already filled in. Replace them with your own.
What the result means
- Outside the ICU
- ADA 2024 glycemic goal 100-180 mg/dL.
- ICU
- ADA 2024 glycemic goal 140-180 mg/dL for most; 110-140 mg/dL for selected patients if reached without significant hypoglycemia.
What you enter
- Current BG
- Target BG
- ISF (mg/dL per unit; blank derives from TDD)
- Total daily insulin dose
- ISF rule (when derived from TDD)
- Carbs to be eaten (omit for a correction-only dose)
- Insulin-to-carb ratio (only used when carbs are entered)
How this is calculated
Citation
American Diabetes Association. Standards of Care in Diabetes - 2024: 16. Diabetes Care in the Hospital. Diabetes Care. 2024;47(Suppl 1):S295-S306 (glycemic goals, rec. 16.4-16.5). The 1800 and 1500 rules for deriving an ISF are bedside rules of thumb; the Standards do not state them. Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.