Lesson overview
Ratio and Proportion Dosage Calculations
Ready when you are
Start with short teaching slides, then answer the lesson questions. Your progress stays on this browser.
Learning outcomes
What you will learn
- Identify the known medication ratio.
- Keep dose aligned with dose and quantity aligned with quantity.
- Cross-multiply and solve for the unknown.
- Carry the answer unit through the calculation and check the result.
Clinical connection
Why this matters
Ratio and proportion is a common nursing-school method. It makes the available relationship visible and asks what equivalent amount would contain the ordered dose.
Quick concept
How ratio and proportion works in dosage calculations
Write the available dose and quantity as one ratio, then write the ordered dose and unknown quantity in the same positions. Set the ratios equal, cross-multiply and solve the unknown.
Formula
available dose / available quantity = ordered dose / x quantity
Worked example
Educational example: 250 mg in 5 mL; order 500 mg.
250/5 = 500/x → 250x = 2500
Answer: x = 10 mL
Keep equivalent units aligned and verify the clinical inputs separately from the arithmetic.
Lesson plan
How the lesson works
- 1
Learn
Short teaching slides explain one idea at a time with plain-language examples.
- 2
Practise
Answer calculation or scenario questions and receive immediate feedback.
- 3
Finish
Complete the lesson check and save your learning progress on this browser.
Keep going
Learn, practise, apply and check this skill
Use the page that matches what you need next. Each resource has a different job, so the lesson can stay focused on teaching the skill.
Practise
Ratio & Proportion Practice
Use the dedicated practice surface for additional ratio/proportion questions.
Understand
Medication Calculation Methods Guide
Compare ratio/proportion with the other common calculation methods.
Compare
Choosing a Calculation Method
See one dosage relationship organised three ways.