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

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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

• Dosage Calculation for the ExamDrip rate · mL × drop factor ÷ min · 500 × 20 ÷ 240 = 41.67 → 42 gtt/min
• 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.

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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.