1800 Rule Correction Factor Calculator
Estimate how far 1 unit of rapid insulin lowers glucose from your total daily dose.
Your result
The 1800 rule is a rough starting estimate. Your clinician may use a different formula or a 1500 or 1700 variant depending on your insulin needs.
Medical disclaimer: This tool is for education and is not medical advice. Read more.
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Frequently asked questions
What does the 1800 Rule Correction Factor Calculator do?
Estimate how far 1 unit of rapid insulin lowers glucose from your total daily dose. Enter your values and the result and chart update instantly.
How accurate is it?
It uses published, widely used formulas. Results are estimates for education and planning, not a diagnosis. Talk to a qualified clinician about decisions affecting your health.
Is my information stored or shared?
No. All calculations run in your browser and nothing you type is sent to a server or saved.
What can I search to find this tool?
People find it by searching for: 1800 rule insulin; correction factor from tdd; insulin sensitivity factor.