💉 Insulin Calculator

Calculate days supply or quantity based on your insulin needs

🔬 Concentration:
📊 Units Per Day:
📅 DAYS SUPPLY
or
📦 QUANTITY
Days Supply
0
days
Based on 5 units/day with 100u/mL concentration

💡 Tip: 1 mL = concentration units. Higher concentration means more doses per mL.

Insulin Calculator | Days Supply & Quantity Tool - 2026
Free Diabetes Management Tool - 2026 Updated

Insulin Calculator: Days Supply & Quantity Tool

Calculate your insulin days supply or required quantity based on your daily units and concentration from 100u/mL to 500u/mL. Essential for diabetes management, prescription planning, and pharmacy refills.

Used by 25k+ Diabetics 4.8/5 Rating 100% Free No Signup Required

Understanding Insulin Concentrations

100u/mL
Standard U-100 Insulin
200u/mL
U-200 Concentrated Insulin
300u/mL
U-300 Toujeo / Tresiba
500u/mL
U-500 Humulin R - Severe Insulin Resistance

How to Use the Insulin Calculator

Calculate Days Supply

Enter your insulin concentration (100u/mL, 200u/mL, 300u/mL, or 500u/mL) and your total units per day. Then enter the total quantity of insulin you have in milliliters. The calculator will tell you exactly how many days your insulin will last.

Formula: Days Supply = (Total Quantity x Concentration) / Units Per Day

Calculate Required Quantity

Enter your insulin concentration and units per day. Then enter the number of days you need your insulin supply to last. The calculator will tell you exactly how much insulin in milliliters you need to order or refill.

Formula: Quantity Needed = (Units Per Day x Days) / Concentration

Insulin Calculation Formula (2026 Standard):
Days Supply = (Total mL x Concentration) / Units Per Day
Quantity Needed = (Units Per Day x Days) / Concentration

Why Insulin Concentration Matters

U-100 (100u/mL)

Standard concentration for most insulin pens and vials. Each milliliter contains 100 units of insulin. Most commonly prescribed for Type 1 and Type 2 diabetes patients.

U-200 and U-300 (200-300u/mL)

Concentrated insulins that allow you to inject less volume for the same number of units. Ideal for patients requiring high daily doses of 60 or more units per day.

U-500 (500u/mL)

Highly concentrated insulin for patients with severe insulin resistance who typically require 200 or more units per day. Only used under strict medical supervision.

Essential Insulin Management Tips for 2026

Storage and Handling

  • Store unopened insulin in refrigerator between 36°F and 46°F (2°C to 8°C)
  • Opened insulin can be kept at room temperature for up to 28 days
  • Never freeze insulin as frozen insulin loses potency
  • Keep insulin away from direct sunlight and heat sources
  • Check expiration dates before each use

Prescription and Refill Planning

  • Refill 7 to 10 days before your insulin runs out
  • Set recurring refill reminders on your phone
  • Use pharmacy auto-refill programs when available
  • Request early refill from your doctor when traveling
  • Keep a backup supply for emergencies of at least 7 days

Common Insulin Dosing Scenarios - 2026 Guidelines

Type 1 Diabetes - Typical

Typical daily dose: 30 to 60 units per day
Common concentration: U-100
30-day supply needed: 9 to 18 milliliters (1 to 2 vials)

Type 2 Diabetes - Typical

Typical daily dose: 20 to 80 units per day
Common concentration: U-100 or U-200
30-day supply needed: 6 to 24 milliliters (1 to 3 vials)

High Dose - Insulin Resistance

Typical daily dose: 100 to 300 units per day
Recommended concentration: U-300 or U-500
30-day supply needed: 6 to 18 milliliters (1 to 2 pens)

Critical Safety Warning: Never change your insulin concentration or dosage without consulting your doctor. Using the wrong concentration such as U-500 instead of U-100 can cause severe hypoglycemia or hyperglycemia. Always double-check your insulin vial before each injection.

Frequently Asked Questions About Insulin Calculators

How do I calculate how many days my insulin will last?
Use the formula: Days Supply = (Total milliliters x Concentration) / Units Per Day. For example, if you have 10mL of U-100 insulin and take 40 units per day: (10 x 100) / 40 = 25 days.
What is the difference between U-100, U-200, U-300, and U-500 insulin?
These numbers represent the concentration or how many units of insulin are in 1 milliliter. U-100 has 100 units per milliliter which is standard. U-200 has 200 units per milliliter which is more concentrated. U-300 and U-500 are even more concentrated for patients requiring higher doses.
How often should I refill my insulin prescription?
Most insurance plans allow refills when you have 7 to 10 days of insulin remaining. Use our calculator to track your supply and set refill reminders to avoid gaps in treatment.
Can I use this insulin calculator for pump users?
Yes. Insulin pump users can also use this calculator. Just enter your total daily insulin dose including basal and bolus and your insulin concentration which is typically U-100 for most pumps.
What happens if I use the wrong insulin concentration?
Using the wrong concentration can be dangerous. For example, injecting U-500 insulin using a U-100 syringe would give you 5 times the intended dose, potentially causing life-threatening hypoglycemia. Always verify your concentration before each injection.
How do I know which insulin concentration is right for me?
Your doctor will prescribe the appropriate concentration based on your daily insulin requirements, insulin sensitivity, and medical history. Never switch concentrations without medical supervision.
Does insurance cover all insulin concentrations?
Most insurance plans cover standard U-100 insulin. Higher concentrations such as U-200, U-300, and U-500 may require prior authorization. Check with your insurance provider and doctor for coverage details.
How should I store my insulin?
Store unopened insulin in the refrigerator between 36°F and 46°F. Opened insulin can be kept at room temperature below 86°F for up to 28 days. Never freeze insulin or expose it to direct heat or sunlight.

Helpful Diabetes Management Resources for 2026

Professional Organizations

  • American Diabetes Association (ADA)
  • CDC Diabetes Prevention Program
  • JDRF Type 1 Diabetes Research
  • Association of Diabetes Care and Education Specialists

Helpful Tools and Apps

  • Insulin calculators like this one
  • Carb counting applications
  • Continuous glucose monitor (CGM) applications
  • Prescription refill reminder applications
Medical Disclaimer: This insulin calculator is for informational and educational purposes only. It does not constitute medical advice. Always consult your healthcare provider, endocrinologist, or pharmacist before making any changes to your insulin dosage, concentration, or refill schedule. Insulin requirements vary based on diet, activity, illness, and other factors. In case of medical emergency, call 911 immediately.