How the calculation works
Daily lenses per month = box price ÷ lenses × 30 × eyes; monthly lenses per month = box price ÷ (lenses × 30) × 30 × eyes + solution per month; difference over 12 months = monthly difference × 12
A worked example
90 daily lenses at €45.00 are €0.50 per wearing day: €30.00 a month for both eyes. Six monthly lenses at €30.00 are €10.00 a month for both eyes, €18.00 with €8.00 of solution. The monthly lenses save €12.00 a month, €144.00 over 12 months.
What the comparison leaves out
Daily lenses need no solution and no case; monthly lenses need both, every night. That is the whole difference this tool adds. Whether a daily or a monthly lens suits your eyes, and which ones your prescription allows, is not a price question.
Your prescription comes first
Buy only the brand, base curve, diameter and power on your current prescription; see an eye-care professional for fitting and follow-up. A cheaper lens that is not on your prescription is not a saving: brand, material, base curve and diameter all change how a lens sits on the eye.
Common questions
Are monthly lenses always cheaper?
Per wearing day, usually: a monthly lens spreads its price over 30 days. Solution narrows the gap, and cheap daily lenses in large boxes can come close. Enter your own prices to see.
What if I only wear lenses some days?
Then daily lenses cost only for the days you wear them, while a monthly lens still has to be replaced on schedule once opened. This calculator assumes daily wear every day.
Method: arithmetic from the label values you enter. Reviewed .