Drug Calculations

Drip Rate (drops/min) Calculator

Gravity-drip flow in drops per minute from volume, time and the tubing drop factor.

Reviewed by Alex G, BSN, RN, CEN, CCRN, CMC, NREMT-P · From the Reference tab of the app

Turn on JavaScript to use this calculator, or open it in the web app.

Formula

(Volume * Drop Factor) / Time

How it is used

• gtt/min = volume (mL) × drop factor (gtt/mL) ÷ time (min). Example: 500 mL over 4 h (240 min) on 20 gtt/mL tubing is 41.67, so 42 gtt/min.
• The drop factor is printed on the tubing package: macrodrip sets deliver 10, 15 or 20 gtt/mL, microdrip sets 60 gtt/mL.
• With microdrip tubing gtt/min equals mL/h; count drops for a full minute and recount after the patient moves.

Same formula as the app. Open it in the web app.

Related one-pagers

• ICU Report Sheet: SBAR Brain Sheet for NursesDrips · Drug, concentration, dose, rate in mL/h, titration goal, line and port
• CRRT (Continuous Renal Replacement)The machine removes exactly what it is set to; the patient's balance is that minus everything else. Each hour, total intake (every drip, feed, flush, blood product, citrate and calcium) and output (urine, drains, stool, NG), then set the next hour's removal so the running total moves toward the goal set on rounds (Prowle and Mehta 2021). Hold or cut removal for a falling MAP or rising pressor. Rates above about 1.75 mL/kg/h carried higher mortality in RENAL data (Murugan 2019): a 70 kg patient rarely needs more than 120 mL/h outside pulmonary edema.
• DKA and HHSThe chloride in saline produces a normal-gap acidosis that can hold the drip after ketones clear. Balanced crystalloids (lactated Ringer's, Plasma-Lyte) resolved DKA faster in the SMART/SALT-ED subgroup and a meta-analysis, and earlier in SCOPE-DKA, whose 48 h primary outcome was not significant (see Evidence); the acetate in Plasma-Lyte did not raise ketones. The 2024 consensus accepts either fluid, and the 4–5 mEq/L of potassium in balanced solutions is no reason to avoid them. For HHS, JBDS keeps 0.9% saline as the main fluid because it is hypotonic relative to the patient's serum.

Drip cards with a dose ↔ mL/h converter

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For education and exam preparation only. Follow your institution’s protocols. For education and exam preparation only. Verify results independently and follow your institution’s protocols. Not a substitute for clinical judgment.