๐ Household
Sunscreen Calculator
Dermatologists use a rule of thumb of about one ounce, or a full shot glass, to cover an adult body in a swimsuit. Most people apply a quarter of that, which effectively cuts the labelled SPF to a fraction of its value.
How it works
Body weight
Coverage
SPF
Hours in the sun
Sunscreen per application
Sunscreen per application
Applications needed
Total sunscreen for the day
Real protection if applied thin
Frequently asked questions
How do I use the Sunscreen Calculator?
Fill in the fields above โ the result recalculates instantly as you type. Everything runs in your browser, so the values you enter are never collected or stored.
Is this calculator free?
Yes. It is completely free, requires no account, and works on phones, tablets and desktops.