Rex says
Same equations the textbooks use — just way less awkward. Pop in your stats and I'll tell you what the number actually means for you.
Try a scenario
Click to load — tweak from there.Inputs
Result
Estimated total daily dose
34.0
Suggested basal dose
17.0
Suggested total bolus dose
17.0
Bolus per meal
5.7
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One click, a permanent link with your numbers baked in.
How to use this
- 1Enter weight (kg).
- 2Enter starting factor.
- 3Enter meals per day.
- 4Read your estimated total daily dose on the right — it updates as you type.
- 5Hit Share to keep the scenario or send it to someone.
About this calculator
This estimates a starting total daily insulin dose (TDD) from body weight, a common approach when initiating or transitioning a patient onto a basal-bolus insulin regimen, then splits it into basal and mealtime bolus components using standard convention (roughly half basal, half bolus split across meals). Typical weight-based starting estimates run 0.3-0.5 units/kg/day for many type 2 diabetes patients, 0.4-0.6 units/kg/day for hospitalized patients requiring basal-bolus dosing, and often lower (0.2-0.4 units/kg/day) for insulin-sensitive, renally impaired, elderly, or newly diagnosed patients where hypoglycemia risk is a greater concern than hyperglycemia. This is a starting-point estimate only — actual insulin requirements vary enormously by insulin resistance, residual beta-cell function, steroid use, infection, and other factors, and doses should be titrated based on glucose monitoring, not fixed at the calculated starting value. This tool is for education and workflow support only — not medical advice. Always verify results with a clinician and use clinical judgment alongside your institution's protocols.
Worked example
Using the values the calculator loads with:
Inputs
- Weight: 85 kg
- Starting factor: Typical starting estimate (0.4 u/kg)
- Meals per day: 3
Results
- Estimated total daily dose: 34
- Suggested basal dose: 17
- Suggested total bolus dose: 17
- Bolus per meal: 5.7
What each field means
Inputs
- Weight (kg)
- The weight used in the calculation, measured in kg. Starts at 85 kg so you have a working example on load. Accepted range: 20–250 kg.
- Starting factor
- Pick the option that matches your situation — the maths changes per option. Choices: Conservative / hypoglycemia risk (0.2 u/kg), Lower estimate (0.3 u/kg), Typical starting estimate (0.4 u/kg), Higher estimate (0.5 u/kg), Insulin-resistant / higher need (0.6 u/kg).
- Meals per day
- The meals per day used in the calculation. Starts at 3 so you have a working example on load. Accepted range: 1–5.
Results
- Estimated total daily dose
- Returned as a decimal number and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Suggested basal dose
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Suggested total bolus dose
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Bolus per meal
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
Is 0.5/0.5 always the right basal/bolus split?
It's the most common starting convention, but some patients — especially those eating very little, on continuous tube feeds, or with erratic oral intake — may need a higher proportion of basal relative to bolus. The split should be reassessed based on actual glucose patterns, not left fixed indefinitely.
Why would I choose a lower starting factor like 0.2 units/kg?
Elderly patients, those with renal impairment (which prolongs insulin clearance), newly diagnosed patients with residual beta-cell function, or anyone where a hypoglycemic event would be especially dangerous (falls risk, hypoglycemia unawareness) generally warrant a more conservative starting dose with closer titration upward as needed.
Does this apply to type 1 diabetes?
The same weight-based starting logic is sometimes used at diagnosis or during transitions, but type 1 diabetes patients are generally more insulin-sensitive and prone to hypoglycemia than type 2 patients on this dosing range, so many protocols start type 1 patients at the lower end (around 0.4-0.5 units/kg/day total) with careful titration and structured carb-ratio dosing rather than a flat estimate.
What should happen after starting at this estimated dose?
Glucose should be monitored closely (typically before meals and at bedtime, or continuously with a CGM) and the total dose, basal/bolus split, and individual meal ratios adjusted every few days based on the pattern of highs and lows — this estimate is only meant to get a reasonable, safe starting point, not a final regimen.
Accuracy and limitations
- Population formulas describe averages; individual bodies vary, especially at the extremes of height, age, or muscle mass.
- Results do not account for medical conditions, medication, or pregnancy.
- Use this as a directional reference, not a diagnosis — talk to a clinician before acting on it.
Related tools
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Extra rapid-acting insulin needed to bring a high glucose to target.
Ideal Body Weight Calculator (Devine Formula)
Devine formula IBW used for drug dosing and ventilator settings.
Adjusted Body Weight Calculator
Dosing weight for obese patients that blends actual and ideal weight.
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Total Daily Insulin Dose Estimator. Retrieved from https://www.revenuelab.fyi/toolbox/total-daily-insulin-dose
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/total-daily-insulin-dose" target="_blank" rel="noopener">Total Daily Insulin Dose Estimator — RevenueLab</a> (2026).</p>
Source: [Total Daily Insulin Dose Estimator — RevenueLab](https://www.revenuelab.fyi/toolbox/total-daily-insulin-dose) (2026).