Insulin Pump Calculator

Insulin pump settings are traditionally built outward from one number: the Total Daily Dose (TDD), the sum of everything a person on multiple daily injections was using across basal and bolus insulin before starting a pump. This calculator applies the standard pump-initiation rules of thumb built around that number. Basal rate assumes roughly half of TDD covers background insulin needs, spread evenly across 24 hours. The Insulin-to-Carb Ratio (ICR) uses the "500 rule" (500 divided by TDD, giving grams of carbohydrate covered by one unit) -- the standard rule for rapid-acting insulin analogs, the kind almost universally used in pumps because of their faster onset and shorter duration; the alternative "450 rule" is used for Regular (short-acting, non-analog) insulin instead.

The Insulin Sensitivity Factor (ISF, or correction factor) uses the "1800 rule" (1800 divided by TDD), estimating how many mg/dL one unit of rapid-acting insulin will lower blood glucose; the alternative "1500 rule" is generally used for regular (non-analog) insulin instead. From there, meal bolus is simply carbohydrates divided by ICR, and correction bolus is the gap between current and target glucose divided by ISF, floored at zero so a below-target reading never produces a negative bolus recommendation. These are starting-point formulas meant to be fine-tuned against real glucose patterns during clinical follow-up, not fixed prescriptions -- insulin resistance, activity level, and illness can all shift the ratios a given patient actually needs.