Clinical tool
Insulin Calculations
Weight-based starting estimates for a basal-bolus insulin regimen.
Enter weight and a starting factor to see the estimated insulin doses.
What this calculates
Weight-based estimates for a basal-bolus insulin regimen: total daily dose, a 50:50 basal and bolus split, the 100 rule correction factor and the 500 rule carbohydrate ratio.
When to use it
To get a starting point when initiating or reviewing a basal-bolus regimen in an adult who is not in a hyperglycaemic emergency.
How to interpret it
The total daily dose is weight multiplied by the chosen factor (commonly 0.3 to 0.6 units/kg/day). Treat every figure as a starting estimate to be titrated against glucose monitoring.
Important limitations
- Not for DKA or HHS, which use a weight-based infusion under a separate protocol.
- Reduce the starting factor in renal or hepatic impairment, older adults and anyone prone to hypoglycaemia.
- The 100 and 500 rules were derived for type 1 diabetes and apply poorly to many type 2 regimens. Check every dose against local policy.
For practising medics only. Clinical tools support judgement, they do not replace it. Always verify results against current guidelines and the patient in front of you.