Free sunscreen tools, built on the same rule as everything else on Seoullit: every number traces to a source you can open. No ads, no sign-ups. Each tool explains its own methodology at the bottom of its page, and links back to the full guide that covers the topic in depth.
Sunscreen amount calculator
Pick the areas you’ll expose and get your dose in teaspoons and milliliters, built on Cancer Council and AAD guidance. The answer surprises most people.
Korean sunscreen match quiz
Three questions, one pick from our published guides, with the reasoning and sources one click away. Includes affiliate links in results, disclosed on the page.
SPF time calculator
How long sunscreen really lasts, and what your SPF 50 delivers at the amount most people actually apply. Straight math, no countdown myths.
Filter name converter
Tinosorb, Uvinul, bemotrizinol, and the long INCI names on Korean labels: one searchable table with each filter’s US status.
Expiry and PAO calculator
Printed date, the 12M open-jar symbol, or no date at all: enter what you know and get a use-by verdict, built on FDA and EU labeling rules.
Double cleanse checker
Whether tonight needs an oil step, answered with lab measurements of how much sunscreen each washing method actually removes.
Reapply planner
Your hours outside, turned into a first-application time and 2-hour top-up schedule you can set alarms for.
Skin type test
Five behavior questions to find your skin pattern, then a handoff to the guide and quiz written for it. Pattern matching, not a diagnosis.
Cost per month calculator
Price divided by real-dose lifespan. Also catches the opposite problem: a bottle that lasts too long means the dose is short.
New to Korean sunscreen? Start with the complete beginner guide.