IV Drip Rate Calculator (gtt/min)
Compute the gravity-IV drip rate in drops per minute (gtt/min) from a total volume, an infusion time, and the drop factor of the giving set (10, 15, 20, or 60 gtt/mL).
(vol mL × drop gtt/mL) ÷ time min
set this if using a pump instead of gravity
Drop factor on the giving-set package — common values 10 (blood sets), 15 (std macrodrip), 20, 60 (microdrip / paediatric). Clinical decision support tool — confirm against your local protocol and the giving-set label; not a substitute for clinical judgment.
General calculation reads
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About this tool
A gravity-fed IV (without an infusion pump) is regulated by counting drops at the drip chamber. To pick the right rate you need three things: the total volume to infuse, the infusion time, and the drop factor of the giving set — the number of drops it takes to deliver one millilitre, printed on the giving-set package. The formula is gtt/min = (volume mL × drop factor gtt/mL) ÷ time (min). This calculator does the arithmetic for you and shows the mL/hr equivalent (the rate you would set on a pump) and the seconds-per-drop count nurses actually use at the bedside — counting how many drops fall in 15 seconds, multiplied by four, gives the drip rate. Common drop factors are 10 gtt/mL for blood sets, 15 gtt/mL for standard macrodrip, 20 gtt/mL for some adult sets, and 60 gtt/mL for microdrip (pediatric, small-volume). This is a clinical decision support tool — confirm against your local protocol and the giving-set label; not a substitute for clinical judgment.
How to use it
- Enter total volume (mL).
- Enter infusion time (h:m or minutes).
- Pick the drop factor printed on the giving set (10, 15, 20, or 60 gtt/mL).
- Read drops per minute, the seconds-per-drop count for the bedside check, and the mL/hr pump-equivalent rate.
Frequently asked questions
- What is the drop factor?
- The number of drops the giving-set chamber delivers per millilitre. It is printed on the package: macrodrip sets are usually 10, 15, or 20 gtt/mL; microdrip sets are 60 gtt/mL.
- When should I use a microdrip set?
- Microdrip (60 gtt/mL) is used for pediatric, neonatal, or low-volume infusions where small rate errors matter. The 60 gtt/mL ratio means 1 mL/hr = 1 gtt/min, which makes the bedside arithmetic trivial.
- How do nurses verify the rate at the bedside?
- Count drops in the drip chamber for 15 seconds and multiply by four. The calculator reports the target 15-second count.
- What is the formula?
- gtt/min = (volume mL × drop factor gtt/mL) ÷ time (min). Example: 1000 mL over 8 hours (480 min) with a 15 gtt/mL set = 1000 × 15 ÷ 480 = 31.25 ≈ 31 gtt/min.
- When do you need an infusion pump instead?
- For drugs with narrow therapeutic windows (vasopressors, insulin, chemotherapy), high-precision rates, or volumetric accuracy. Gravity infusion has natural variability of several percent depending on bag height and patient movement.
- Is any data sent anywhere?
- No. Calculation runs in your browser.