Before using this rule, please read the WARNING statement in Section 1.
Use the handy calculation tool to the right to find your blood sugar/insulin ratio based on the 1500 Rule by entering your total daily insulin use (TDIU) in the entry box and clicking on SUBMIT or follow the instructions for the graph below to look up your blood sugar/insulin ratio.
Instructions for using the 1500 Rule Graph
Find your total daily insulin use (TDIU) on the horizontal scale at the bottom of the graph. From your TDIU draw a line vertically up until it intersects the red curve. From the intersection point on the curve, draw a line horizontally to the left until it intersects the Blood Sugar/Insulin Ratio scale and note the number. This is your blood sugar to insulin ratio based on the 1500 Rule. Note: If you use mmol/l as units for BG measurement, use the scale to the right rather than the left.
Humalog users may wish to use the 1800 Rule instead of the 1500 Rule to estimate Blood Sugar / Insulin ratios. A discussion of the 1800 Rule is included in the article Changing To Humalog?, What You Need To Know On A Pump by John Walsh, P.A., C.D.E., and Ruth Roberts, M.A.