Total Daily Insulin Dose Calculator
Total Daily Insulin Dose Calculator
A weight-based STARTING total daily dose for a prescriber initiating insulin, from the figures the ADA publishes rather than the narrower range that circulates — and the basal-bolus split that then feeds the sensitivity factor and the carbohydrate ratio. Type 2 diabetes is a different pathway on this page, not a smaller version of the same one.
Starting total daily insulin dose
Weight × units/kg → starting doseType 1 diabetes, 70 kg, 0.5 units/kg/day
Formula
Basal insulin ≈ 50% of the total · prandial insulin ≈ 50%, divided between meals
Then: ISF (mg/dL per unit) ≈ 1800 ÷ total daily dose · carbohydrate ratio (g per unit) ≈ 500 ÷ total daily dose
- type 1 diabetes
- ADA: "typical doses ranging from 0.4 to 1 unit/kg/day", with "0.5 units/kg/day as a typical starting dose in adults with type 1 diabetes who are metabolically stable"
- lower than that
- ADA: 0.2 to 0.6 units/kg, "particularly in young children and those with continued endogenous insulin production (during the partial remission phase or 'honeymoon period', or in people who present with type 1 diabetes in adulthood)"
- higher than that
- ADA: starting doses "may be higher, if an individual presents with ketoacidosis", and "higher amounts may be required during puberty, menses, and medical illness". Pregnancy changes the requirement continuously through gestation
- type 2 diabetes
- a different pathway. ADA: basal insulin started at 0.1 to 0.2 units/kg/day "and the degree of hyperglycemia, with individualized titration over days to weeks", titrated against the fasting glucose. Basal only at initiation; no prandial insulin, no 50/50 split
- the split
- ADA: "approximately one-half administered as prandial insulin ... and the remaining portion as basal insulin". Pump data from people at target put basal at 47 to 48% of the total
- children
- not published here. Age-banded paediatric dosing needs ISPAD's guidance or the local paediatric protocol, and is not a weight multiplication
Worked example
Type 1 diabetes, 70 kg, 0.5 units/kg/day
70 × 0.5 = 35 units/day as a starting total daily dose
Basal, at about half: 17 to 18 units/day
Prandial, the other half: about 17 units divided between meals, so roughly 6 units per meal before adjusting for what is actually eaten
That total then sets the two bolus-calculator settings: sensitivity factor ≈ 1800 ÷ 35 = 51 mg/dL (2.9 mmol/L) per unit, carbohydrate ratio ≈ 500 ÷ 35 = 14 g per unit
Every one of those numbers is a starting point. The prescriber titrates all of them against measured glucose from day one
If the same 70 kg person had type 2 diabetes, the starting dose would be 0.1 to 0.2 units/kg/day — 7 to 14 units of basal insulin only, titrated against the fasting glucose
What the ADA actually publishes
| Situation | Starting dose | Note |
|---|---|---|
| Type 1 diabetes, metabolically stable adult | 0.5 units/kg/day | Described as the typical starting dose, within a typical range of 0.4 to 1.0 units/kg/day |
| Type 1 diabetes — young children, partial remission, adult-onset type 1 | 0.2 – 0.6 units/kg/day | Continued endogenous insulin production reduces the requirement. It will rise as that declines |
| Type 1 diabetes presenting with ketoacidosis | Higher | The ADA states starting doses may be higher; the acute management of ketoacidosis is a separate protocol entirely and is not this calculation |
| Type 1 diabetes in puberty, menses, intercurrent illness | Higher amounts may be required | These move the maintenance requirement rather than defining a starting dose |
| Type 2 diabetes, starting basal insulin | 0.1 – 0.2 units/kg/day | Basal only, judged alongside the degree of hyperglycaemia, titrated over days to weeks against the fasting glucose |
Starting dose by weight (type 1 diabetes, 0.5 units/kg/day)
| Weight | Total daily dose | Basal ≈ 50% | Per meal ≈ 17% | ISF (1800 rule) | Carb ratio (500 rule) |
|---|---|---|---|---|---|
| 50 kg | 25 units/day | 12 – 13 units | 4 units | 72 mg/dL (4.0 mmol/L) | 20 g/unit |
| 60 kg | 30 units/day | 15 units | 5 units | 60 mg/dL (3.3 mmol/L) | 17 g/unit |
| 70 kg | 35 units/day | 17 – 18 units | 6 units | 51 mg/dL (2.9 mmol/L) | 14 g/unit |
| 80 kg | 40 units/day | 20 units | 7 units | 45 mg/dL (2.5 mmol/L) | 13 g/unit |
| 90 kg | 45 units/day | 22 – 23 units | 8 units | 40 mg/dL (2.2 mmol/L) | 11 g/unit |
| 100 kg | 50 units/day | 25 units | 8 – 9 units | 36 mg/dL (2.0 mmol/L) | 10 g/unit |
Where this calculation does not apply
| Situation | Why not | What to use instead |
|---|---|---|
| Children and adolescents | Requirement varies by age and pubertal stage in a way a single units/kg figure does not capture, and no age-banded schedule is published on this page | ISPAD's insulin guidance, or the local paediatric diabetes protocol |
| Diabetic ketoacidosis | Acute management is a fixed-rate intravenous insulin infusion with fluid and potassium replacement, on a timed protocol | The local DKA protocol. Subcutaneous basal-bolus insulin is started as part of the recovery phase, not at presentation |
| Pregnancy | Insulin requirement changes continuously through gestation and falls abruptly after delivery | A joint diabetes-antenatal service, with frequent review |
| Established diabetes on insulin already | This estimates a STARTING dose. Someone already on insulin has a measured requirement, which is better information than any formula | Their own average delivered dose over at least a week |
| Inpatient, perioperative, or on high-dose glucocorticoids | Requirement moves day to day and often hour to hour | The local inpatient or steroid-hyperglycaemia protocol |
| Concentrated insulin (U-200, U-300, U-500) | The number of units and the volume are no longer in the usual relationship, which is a dispensing and administration hazard rather than a calculation one | Specialist prescribing, with the concentration stated explicitly on every order |
A starting dose, and the pathway it belongs to
This is the page with the most potential to do harm on this site, so it is worth being explicit about what it is. It estimates a STARTING total daily insulin dose for a prescriber initiating insulin, by multiplying body weight by a published units-per-kilogram figure. It is not a maintenance dose, it is not a prescription, and it is not a substitute for the measured requirement of someone already taking insulin — for whom their own average delivered dose over a week is far better information than any formula. If you have diabetes and you are reading this, the number below is not yours; it is an arithmetic estimate of where a clinician might start someone of your weight, and the person who starts it is the person who then titrates it against measured glucose.
The figures come from the ADA's Standards of Care. For type 1 diabetes it gives typical doses ranging from 0.4 to 1.0 units/kg/day, with 0.5 units/kg/day as the typical starting dose in a metabolically stable adult, and approximately one-half of the total given as prandial insulin and the remainder as basal. It lowers that band to 0.2 to 0.6 units/kg where there is continued endogenous insulin production — young children, the partial remission or honeymoon phase, and people who present with type 1 diabetes in adulthood — and raises it where the person presents in ketoacidosis or during puberty, menses and intercurrent illness. Note that the published range runs to 1.0 and not to 0.6: the narrower 0.4-to-0.6 figure that circulates understates requirement in puberty, in pregnancy and during illness, and under-dosing type 1 diabetes produces ketosis, not merely a disappointing glucose.
Type 2 diabetes is a different pathway and not a smaller version of the same one, which is why this page asks which you are initiating before it calculates anything. Insulin in type 2 diabetes is usually started as basal insulin alone, at 0.1 to 0.2 units/kg/day judged alongside the degree of hyperglycaemia, added to existing oral or injectable therapy and titrated over days to weeks against the fasting glucose. Prandial insulin is added later, if at all, when fasting glucose reaches target and the HbA1c does not — which is also the point at which continuing to raise the basal dose stops helping and starts causing nocturnal hypoglycaemia and weight gain. The 50/50 basal-bolus split, the 1800 rule and the 500 rule all describe full insulin replacement in someone who makes none of their own, and none of them belongs on a type 2 basal-only regimen.
Two omissions on this page are deliberate. It publishes no paediatric dose by age band: requirement in children varies with age and pubertal stage in a way that a single units-per-kilogram multiplication does not represent, the age-banded figures could not be verified against their primary source here, and inventing them would be exactly the wrong response to not having them — children should be dosed against ISPAD's guidance or the local paediatric protocol. And it says nothing about how to manage diabetic ketoacidosis, which is a fixed-rate intravenous infusion on a timed protocol with fluid and potassium replacement, not a weight-based subcutaneous dose. The total this page produces does have one further use: it is the denominator for the insulin sensitivity factor and the insulin-to-carbohydrate ratio, so an error in it propagates straight into both of those settings, and a starting dose that was never titrated quietly becomes three wrong numbers instead of one.
Frequently asked questions
What is the starting total daily insulin dose in type 1 diabetes?
The ADA gives 0.5 units/kg/day as the typical starting dose in a metabolically stable adult, within a typical range of 0.4 to 1.0 units/kg/day, with approximately half as prandial insulin and the remainder as basal. Lower, 0.2 to 0.6 units/kg, in young children, in the partial remission phase and in adult-onset type 1 diabetes.
Is the range 0.4 to 0.6 or 0.4 to 1.0 units/kg/day?
The ADA publishes 0.4 to 1.0 as the typical range and 0.5 as the typical starting dose. The narrower 0.4 to 0.6 figure is widely quoted but understates requirement during puberty, pregnancy and intercurrent illness, all of which the ADA specifically notes may need higher amounts.
How is the total split between basal and bolus?
Approximately half and half — the ADA describes about one-half as prandial insulin with the remainder as basal. Retrospective analyses of pump data from people at target put basal at 47 to 48% of the total, close enough to half that the difference is a matter of titration rather than of arithmetic.
How is insulin started in type 2 diabetes?
Differently. Basal insulin alone, at 0.1 to 0.2 units/kg/day judged against the degree of hyperglycaemia, added to existing therapy and titrated over days to weeks against the fasting glucose. No prandial insulin at initiation, no 50/50 split, and the 500 and 1800 rules do not apply because there is no bolus insulin to set them for.
Does this calculator give a paediatric dose?
No, deliberately. Insulin requirement in children varies with age and pubertal stage in a way a single units-per-kilogram figure cannot represent, and no age-banded schedule is published here. Use ISPAD's guidance or your local paediatric diabetes protocol.
Can I use this to work out my own insulin dose?
No. This estimates where a prescriber might start someone of a given weight who is not yet on insulin. If you already take insulin, your own average delivered dose over a week is a much better figure than anything this calculates, and any change to it is a decision for you and your diabetes team.
Does it apply in diabetic ketoacidosis?
No. Ketoacidosis is managed with a fixed-rate intravenous insulin infusion alongside fluid and potassium replacement, on a timed local protocol. Subcutaneous basal-bolus insulin is introduced in the recovery phase, and the ADA notes only that starting doses may be higher in someone who presented that way.
Related calculators
References
- American Diabetes Association Professional Practice Committee. 9. Pharmacologic Approaches to Glycemic Treatment: Standards of Care in Diabetes—2025. Diabetes Care. 2025;48(Suppl 1):S181–S206.
- Davidson PC, Hebblewhite HR, Steed RD, Bode BW. Analysis of guidelines for basal-bolus insulin dosing: basal insulin, correction factor, and carbohydrate-to-insulin ratio. Endocr Pract. 2008;14(9):1095–1101.
- Walsh J, Roberts R, Bailey T. Guidelines for insulin dosing in continuous subcutaneous insulin infusion using new formulas from a retrospective study of individuals with optimal glucose levels. J Diabetes Sci Technol. 2010;4(5):1174–1181.
Medical Disclaimer: The tools and content provided here are for educational and reference purposes only. They are not intended to substitute for professional medical advice, diagnosis, or treatment. Clinical decisions should always be based on the comprehensive assessment of a qualified healthcare professional.