Last Updated on August 5, 2025
Your Total Daily Dose (TDD) is the total amount of insulin you use in 24 hours. Your average TDD helps manage your average glucose and A1c levels, and when properly adjusted, it is your best guide for setting accurate basal and bolus doses. The TDD (also called total daily insulin, total insulin, or daily insulin requirement) can change each day due to variations in food intake and physical activity.
Finding an optimal average TDD over the past two weeks or more provides a helpful metric for adjusting basal rates, long-acting insulin doses, carb-to-insulin ratios, and correction factors. This also enhances dosing decisions.
This article explains TDD and its applications, compares differences across patient profiles (basal vs bolus), highlights recent advances in insulin dosing algorithms and AID systems, and references clinical trials and ADA standards.
What Is TDD?
Total Daily Dose (TDD) refers to the total amount of insulin taken over 24 hours and is best measured as an average over two weeks or more. It includes both:
- Basal insulin – the basal rate or long-acting insulin dose that maintains stable glucose levels by providing background coverage throughout the day and night.
- Bolus insulin – short-acting insulin doses administered for meals or to correct high blood sugar levels.
In Advanced Glucose Profile (AGP) reports for pumps like Tandem’s t:slim X2, TDD is labeled as Total Insulin. Research studies often refer to TDD, 24-Hour Total, or Daily Insulin Requirement.
Why It’s Important
- Starting and adjusting insulin involves estimating the basal and bolus insulin balance as well as carbohydrate ratios (e.g., Insulin to Carb Ratio (ICR or Carb Factor) = 2.4 times weight in lbs (1.1 times weight in kgs) divided by TDD; Correction Factor (Insulin Sensitivity Factor/ISF) = approximately 1800 divided by TDD for an average glucose of 140 mg/dL or 1000 divided by TDD for an average glucose of 300 mg/dL).
- Evaluating insulin sensitivity: A lower TDD per pound or kilogram usually indicates higher insulin sensitivity.
- Tuning Automated Insulin Delivery (AID) systems: Algorithms in hybrid closed-loop pumps rely heavily on accurate TDD values.
How to Find Your Total Daily Dose (TDD)
Your TDD is the total amount of insulin you use in 24 hours. Here’s how to determine or calculate it:
On an AID or an Insulin Pump
- Go to your pump history screen or download your data using pump software like t:Connect, CareLink, or Glooko.
- Look for “Total Insulin” or “24-Hour Total”—this includes both basal and bolus insulin.
- To calculate an average TDD, review data over seven days if your glucose or insulin doses have recently changed, or over 14 to 30 days for a more precise TDD.
With Multiple Daily Injections (MDI)
- Add up all basal (long-acting) insulin taken in 24 hours (e.g., Lantus, Tresiba).
- Add all bolus (rapid-acting) insulin given for meals or corrections.
- Your TDD is the sum of basal and bolus doses.
- An average of 7 or more days of data provides a more accurate TDD if daily doses vary.
Example: If you take 22 units of basal insulin and 18 units of bolus insulin daily, your TDD is 40 units.
Basal vs. Bolus: How It Varies by Age & Device
| Profile | TDD | Basal % | Bolus % | Notes |
|---|---|---|---|---|
| Adult (MDI or Pump) |
0.2-0.28 U/lb |
40–50% | 45–60% | Stable routines; balanced split |
| Child (MDI or Pump) |
0.23-0.46 U/lb |
30–45% | 55–70% | Growth and activity drive variability |
| AID Adult |
0.16-0.28 U/lb |
33–45% | 45–60% | Auto-adjustments reduce TDD needs |
| AID Child |
0.2-0.4 U/lb |
25–35% | 65–75% | Hormones and meals need bolus accuracy |
As a child or teen grows, the TDD must increase with each growth spurt to minimize high glucose levels or DKA, especially as hormone levels rise with puberty. An adult’s TDD also follows any rise or fall in weight.
Common Alternative Terms for TDD
- Total Insulin – Tandem t:slim X2 / Control‑IQ
- 24‑Hour Total – CareLink, Tidepool, pump reports
- Daily Insulin Requirement, Total Units per Day, Insulin Total – EMR and clinical documents
- Average Daily Dose (ADD) – Multi-day averages in research
Strategies for Improving Your TDD (from Pumping Insulin, 7th Ed.)
This guidance is adapted from the 7th edition of Pumping Insulin, a trusted and widely used resource among healthcare professionals and people with diabetes for its practical, evidence-based insulin strategies.
A. Is your TDD already at your goal?
- If TIR exceeds 70% and GV is under 30%, your TDD is correctly tuned.
- Consider further improvement by increasing your TDD by 1–2% and updating AID or pump settings.
B. Are you having frequent lows?
- If you spend more than 4% of the time below 70 mg/dL, reduce your TDD by 5–10%.
- Adjust your basal and bolus balance—reduce the one that is higher and most likely causing the lows.
- Temporarily increase your glucose target and extend DIA to prevent insulin stacking.
| 9.4 For Frequent Lows, Reduce Your TDD | ||||||
|---|---|---|---|---|---|---|
|
Reduce your TDD by 5% or 10% for frequent lows that are mild or more severe, respectively. Find your current average TDD in the left column and go across for a lower TDD from which to get new pump settings in Table 9.7. Multiply your current average TDD by 0.95 for a 5% reduction or by 0.90 for a 10% reduction, as shown in the table below. _____ u/day × 0.95 (or 0.90) = _____ u/day |
||||||
| Current Avg. TDD | 5% Lower TDD | 10% Lower TDD | Current Avg. TDD | 5% Lower TDD | 10% Lower TDD | |
| 20.0 u | 19.0 u | 18.0 u | 55.0 u | 52.4 u | 50.5 u | |
| 25.0 u | 23.8 u | 22.5 u | 60.0 u | 57.1 u | 54.0 u | |
| 30.0 u | 28.5 u | 27.0 u | 65.0 u | 61.9 u | 58.5 u | |
| 35.0 u | 33.3 u | 31.5 u | 70.0 u | 66.7 u | 63.5 u | |
| 40.0 u | 38.1 u | 36.0 u | 80.0 u | 76.2 u | 72.0 u | |
| 45.0 u | 42.9 u | 40.5 u | 90.0 u | 85.7 u | 81.0 u | |
| 50.0 u | 47.6 u | 45.0 u | 100.0 u | 95.0 u | 90.0 u | |
| My new better TDD = ______ units/day. | ||||||
| Keep lowering your TDD every four to seven days until the lows largely disappear. Each time you lower your TDD, use the better TDD to find more appropriate BC settings in Table 9.7. | ||||||
C. Are you at your goal but have excess Glucose Variability?
- If GV >30%, even with good average glucose, focus on stability.
- Bolus early, eat consistent meals, and use settings matched to your TDD.
D. Do you have a high average glucose?
- Calculate your glucose elevation (your average glucose minus your glucose goal), then multiply your current TDD by a percentage from Table 9.6.
- Alternatively, apply the One-for-Five Rule: Increase TDD by 1% for every 5 mg/dL above the target.
Refine your Correction Factor for a better TDD
CorrF = Correction Factor Scale Number ÷ TDD
To correct for high average glucose, use a lower CorrF-ScaleNumber (e.g., 1400 instead of 1800) as glucose levels increase. This allows for more aggressive correction boluses to meet the higher insulin requirements better.
Example: If your Correction Factor Scale Number is 1800 and your TDD is 50 units, then CorrF = 1800 ÷ 50 = 36 mg/dL per unit. This shows that 1 unit of insulin is likely to lower your glucose by about 36 mg/dL.
Use the Online Tool
Visit our interactive tool to calculate better TDDs, basal rates, CarbFs, and CorrFs based on your current data.
Conclusion
Total Daily Dose (TDD) is a crucial metric in insulin therapy, affecting your average glucose, insulin-to-carb ratio, correction factor, and AID/pump performance. Whether you’re using MDI, a pump, or an AID, having an optimal TDD helps refine your insulin doses. Advances in AI, longer-acting insulins, and CGM-integrated AID systems offer even greater control for those living with diabetes.