Questions nursing students actually ask.

Dimensional analysis is a way of solving dosage problems by setting up units so the ones you don't need cancel out, leaving you with the unit the question is actually asking for. It feels different from instructor to instructor mostly because of formatting. Some write it left to right, some stack fractions, but the underlying logic is the same. Start with what you need, find where you already have that unit, and cancel your way there.

This is one of the most common things I see, and it's rarely a math problem. In lecture, the numbers are already organized for you. On a real label or MAR, you have to find the numbers yourself, decide what's relevant, and set the problem up from scratch. That's a different skill from solving a problem someone already framed for you, and it's the one most practice question banks skip entirely.

1 mg equals 1,000 mcg, the same relationship as grams to milligrams. The mistake that causes real harm is misreading one for the other on an order or label, so it's worth slowing down specifically on that line every time, not just doing the math fast. If a dose looks unusually large or small for the medication, that's often the first sign of a unit mix-up.

1 tablespoon = 15 mL, and 1 teaspoon = 5 mL. These come up constantly in patient education for liquid medications, since most people measure at home with kitchen spoons, not a medicine cup. Worth memorizing cold. You'll use it far more often than the more obscure household conversions.

For a gravity infusion, multiply the volume to infuse by the tubing's drop factor, then divide by the time in minutes to get gtt/min. The part people usually miss isn't the math, it's forgetting to convert hours to minutes before dividing. For a pump, it's simpler: volume divided by time in hours gives you mL/hr directly, no drop factor needed.

It's the highest amount of a medication that can be given in a set period, usually 24 hours, without exceeding a safe limit. To check it, divide the maximum by the size of one dose, then round down, never up, since a nurse can't give a partial dose and rounding up would exceed the limit. If a calculated dose is close to the maximum, that's a reason to double-check the order, not just the math.

You can work through real dosage calculation questions on this site without creating an account. Visit Practice to get started. Signing up just adds bookmarks, a saved history, and a review list of questions you haven't quite gotten yet; none of that is required to practice.

Most question banks show you a problem and an answer key. This one is built around showing the thinking in between: every question comes with hints, a full explanation, and a guided walkthrough (Work It With Me) that breaks the problem into the same steps I use when I teach this in person. The goal isn't just getting the right number; it's building the clinical judgment that gets you there reliably, on a real unit, under real time pressure.