Enter Infusion Details
This tool supports weight-based, fixed-dose, volume-based, and gravity infusion checks. Always verify against the medication order, pump library, and local policy.
Example Data Table
| Medication | Weight | Order | Bag Strength | Final Volume | Duration | Estimated Rate |
|---|---|---|---|---|---|---|
| Dopamine | 70 kg | 5 mcg/kg/min | 400 mg | 250 mL | 8 hr | 13.1 mL/hr |
| Heparin | 82 kg | 18 units/kg/hr | 25,000 units | 500 mL | 12 hr | 29.5 mL/hr |
| Magnesium Sulfate | Not needed | 2 g/hr | 20 g | 500 mL | 4 hr | 50.0 mL/hr |
| Potassium Chloride | Not needed | 10 mEq/hr | 40 mEq | 250 mL | 4 hr | 62.5 mL/hr |
| Maintenance Fluid | Not needed | 75 mL/hr | Not required | 1000 mL | 10 hr | 75.0 mL/hr |
Formula Used
1) Standardized Hourly Dose
Hourly dose = ordered dose × patient weight when weight-based. For minute-based orders, multiply the result by 60 to convert to an hourly amount.
2) Solution Concentration
Concentration = total drug amount in the prepared bag or syringe ÷ final solution volume. The calculator converts mass units before dividing.
3) Pump Rate
Pump rate (mL/hr) = standardized hourly dose ÷ solution concentration. A separate rounded rate is also shown using the selected rate increment.
4) Gravity Drip Rate
Drip rate (gtt/min) = rounded mL/hr × drop factor ÷ 60. This is useful for gravity tubing when a pump is not used.
5) Delivered Volume and Drug
Delivered volume = rounded pump rate × duration. Delivered drug = concentration × delivered volume. Bag runtime = bag volume ÷ rounded rate.
How to Use This Calculator
- Enter the medication name and patient weight if the order is weight-based.
- Choose the ordered dose mode, then enter the ordered dose value exactly as written.
- Enter the amount of drug in the final bag or syringe and select the matching unit.
- Enter the final volume after preparation, not only the diluent volume.
- Add the planned infusion duration to estimate volume infused, drug delivered, and remaining bag volume.
- Enter a drop factor to calculate gravity flow in drops per minute.
- Use a rounding increment that matches your pump policy, then compare exact and rounded rates.
- Review all warnings and verify the final result against the medication order and local protocol before administration.
FAQs
1) What does this IV medication calculator estimate?
It estimates pump rate, gravity drip rate, bag runtime, delivered drug amount, fluid volume over time, and projected daily totals from one prepared infusion.
2) When is patient weight required?
Weight is required for dose modes written per kilogram, such as mcg/kg/min, mcg/kg/hr, mg/kg/hr, or units/kg/hr. Fixed-dose and mL/hr entries do not need weight.
3) Why does final volume matter?
Final volume determines concentration. Concentration is what connects the prescribed drug amount to the pump rate, so an inaccurate final volume creates an inaccurate rate.
4) Can I use this for syringe infusions?
Yes. Enter the total drug amount inside the syringe and the final syringe volume. The same concentration and rate logic still applies.
5) What is the rounded pump rate for?
Some pumps or local policies require rounding to a chosen increment, such as 0.1 or 0.5 mL/hr. The calculator shows both exact and rounded values.
6) What if I only know the rate in mL/hr?
Select the mL/hr mode. The calculator will treat the ordered dose as a direct flow rate and can still estimate runtime, infused volume, and drug delivered if concentration is entered.
7) Does the tool replace a drug library or protocol?
No. It is a calculation aid only. Always confirm concentrations, limits, compatibility, and administration instructions against approved references and institutional policy.
8) Why might the calculator show a warning?
Warnings appear when the rounded rate exceeds your own maximum setting, duration uses more than a bag, or rounding changes the exact rate enough to justify rechecking.